All calculators
All 144 live calculators. Search, or filter by field.
Mathematics 10
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Mathematics
Derivative Calculator
Type a function and see its derivative step by step: sum, product, quotient and chain rules, a simplified result, the value at a point and a graph. -
Mathematics
Equation Solver
Type an equation and see the roots step by step: linear, quadratic and cubic, discriminant, complex roots, numeric roots and systems in 2, 3 or 4 unknowns. -
Mathematics
Function Graph Plotter
Type f(x) and see its graph: several functions at once, zoom and pan, roots and intersection points. Download the graph as SVG or PNG. -
Mathematics
Integral Calculator
Compute definite integrals numerically with an error estimate and find antiderivatives symbolically. Every antiderivative is checked by differentiation. -
Mathematics
Matrix Calculator
Matrix addition, multiplication, transpose, determinant, inverse, rank and Gaussian elimination. Exact fraction results with every row operation shown. -
Mathematics
Percentage Calculator
Percent of a number, what percent one number is of another, percent increase and decrease, percent change and reverse percentage. -
Mathematics
Ratio and Proportion Calculator
Finds the unknown in direct and inverse proportion and splits a quantity in a given ratio, with the working shown. -
Mathematics
Right Triangle and Pythagorean Calculator
Solve a right triangle from two sides or from one side and one angle: remaining sides, angles, area, perimeter and altitude. -
Mathematics
Scientific Calculator
Type an expression and see the result at once: trigonometry, logarithms, powers, roots, factorials. Degree and radian modes, memory and history, all in your browser. -
Mathematics
Trigonometry Calculator
Sin, cos, tan, cot, sec and csc of an angle, and the angle from a value with inverse functions. Degrees, radians and gradians.
Physics 24
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Physics
Angular Velocity and Angular Acceleration Calculator
Angular velocity from angle and time, angular acceleration from a change in speed, final speed and number of turns, plus linear speed and accelerations. rpm and rad/s. -
Physics
Circular Motion and Centripetal Force Calculator
Speed, angular velocity, period, frequency, centripetal acceleration and centripetal force in uniform circular motion. From speed, period, rpm or force. -
Physics
Collision Calculator (Elastic and Inelastic)
Final velocities in a one dimensional collision: elastic, perfectly inelastic or with a coefficient of restitution. Momentum and kinetic energy balance with worked steps. -
Physics
Constant Acceleration (SUVAT) Calculator
Enter any three of initial speed, final speed, acceleration, time and displacement to get the other two. Step by step with the kinematic equations. -
Physics
Doppler Effect Calculator
Frequency heard when the sound source or the observer moves: f' = f (v + vo) / (v − vs). Approaching and receding cases, the frequency shift and worked steps. -
Physics
Force, Mass and Acceleration Calculator (F = m × a)
Newton's second law: enter any two of force, mass and acceleration to get the third. Step by step solution with unit conversion. -
Physics
Free Fall Calculator
Enter height, fall time or impact speed to get the other two. h = ½ g t², v = g t. Air resistance is neglected. -
Physics
Friction Force Calculator
Friction force F = μ × N. Friction from mass on a level surface, solving for the coefficient, and a will it move check with static and kinetic friction. -
Physics
Heat and Specific Heat Calculator (Q = m c ΔT)
Heat required, final temperature, specific heat or mass from Q = m × c × ΔT. Approximate specific heats for water, ice, aluminium, iron and copper, or enter your own. -
Physics
Ideal Gas Law Calculator (PV = nRT)
Pressure, volume, amount or temperature from PV = nRT, plus the combined gas law for a change of state (P₁V₁/T₁ = P₂V₂/T₂). Celsius input is converted to kelvin for you. -
Physics
Inclined Plane Calculator
Weight components, normal force, friction and acceleration on an inclined plane. Will it slide, the angle of repose, the force to pull it up and the speed at the bottom. -
Physics
Kinetic Energy Calculator
Kinetic energy from mass and speed (E = ½ m v²), or solve for speed or mass from energy. Accepts km/h and mph, with steps. -
Physics
Momentum and Impulse Calculator
Momentum p = m × v, impulse J = F × Δt, average force from a change in momentum and final velocity from an impulse. Signed velocities, worked steps. -
Physics
Pendulum Period Calculator
Period of a simple pendulum, T = 2π√(L/g). Solve for length or gravity from the period, get the frequency and see the small angle error at large amplitude. -
Physics
Potential Energy Calculator
Gravitational potential energy from mass and height (E = m g h), or solve for height or mass from energy. Step by step solution. -
Physics
Projectile Motion Calculator
Range, maximum height, time of flight and impact speed from initial speed, launch angle and launch height. With a scaled trajectory drawing and worked steps. -
Physics
Simple Harmonic Motion Calculator
Position, velocity and acceleration at any time from amplitude and period or frequency. Angular frequency, maximum speed and acceleration, using x = A cos(ωt + φ). -
Physics
Sound Intensity and Decibel Calculator
Decibels from sound intensity and back (L = 10 log I/I₀). Level from source power and distance, the drop with distance and adding two sound levels. -
Physics
Speed of Sound and Wavelength Calculator
Speed of sound in air from temperature (v = √(γRT/M)), the wavelength of a sound, the time to cover a distance and the echo time. Handy for lightning distance. -
Physics
Speed, Distance and Time Calculator
Enter any two of speed, distance and time to get the third. v = d / t. Works in km/h, m/s, mph and knots with a step by step solution. -
Physics
Spring Mass System Calculator
Period of a mass on a spring, T = 2π√(m/k), with frequency, maximum speed and energy. Spring force from Hooke's law, spring constant from the period and static stretch. -
Physics
Thermal Equilibrium Calculator
Final temperature and heat exchanged when two materials at different temperatures are mixed or put in contact. Find an unknown specific heat from a calorimetry experiment. -
Physics
Wavelength, Speed and Frequency Calculator
Wavelength, frequency or wave speed from the wave equation v = f × λ. For sound, light, radio and water waves. With period and worked steps. -
Physics
Work, Energy and Power Calculator
Work from force and distance (W = F d cos θ), power from work and time (P = W / t), power from force and speed (P = F v). Step by step.
Geometry 3
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Geometry
Area and Perimeter Calculator
Area and perimeter of a rectangle, circle, triangle, trapezoid, ellipse, circular sector, ring and regular polygon, with formulas and working. -
Geometry
Triangle Calculator: Sides, Angles, Area
Solves a triangle from three known values: remaining sides, angles, area, perimeter and altitudes, with a scale drawing and the two solution case. -
Geometry
Volume and Surface Area Calculator
Volume and surface area of a box, cylinder, sphere, cone, truncated cone and pyramid, in cubic metres or litres, with the working shown.
General Calculations and Unit Conversion 1
Mechanical Engineering 17
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Mechanical Engineering
Bearing Equivalent Dynamic Load Calculator
Equivalent dynamic bearing load from radial and axial load: P = X × Fr + Y × Fa. The Fa / Fr ratio is compared with the limit e, factors are entered from the catalogue. -
Mechanical Engineering
Bearing Life (L10) Calculator
Bearing L10 basic rating life in million revolutions and operating hours from dynamic load rating, equivalent load and speed. Also the load rating needed for a target life. -
Mechanical Engineering
Belt Length Calculator
Belt length and wrap angles from two pulley diameters and the centre distance, or the centre distance for a given belt length. Open and crossed belts. -
Mechanical Engineering
Bolt Circle (PCD) Hole Coordinates Calculator
Flange bolt pattern: X and Y of every hole from circle diameter, hole count and start angle. Scaled drawing, hole spacing, CSV export and print. -
Mechanical Engineering
Bolt Tensile and Shear Stress Calculator
Tensile and shear stress, von Mises equivalent stress and safety factor against yield for metric bolts (M3 to M36). Shear through threads or shank. -
Mechanical Engineering
Bolt Tightening Torque and Preload Calculator
Tightening torque and preload for metric coarse bolts (M3 to M36) from property class, percent of yield and torque coefficient. T = K × F × d. -
Mechanical Engineering
Chain Sprocket Ratio and Chain Length Calculator
Ratio and driven speed from sprocket tooth counts. With pitch and centre distance: chain speed, pitch diameters and chain length in links. -
Mechanical Engineering
Gear Ratio and Reduction Ratio Calculator
Gear ratio, output speed and output torque from tooth counts. Total ratio of two or three stage gearboxes, and the ratio needed between two speeds. -
Mechanical Engineering
Gear Teeth Number Calculator
Finds the tooth pair closest to a target ratio, with ratio error and alternatives. Or both tooth counts from centre distance and module. -
Mechanical Engineering
Helical Compression Spring Calculator
Rate, stress under load (Wahl), deflection, solid length and buckling check of a compression spring from wire diameter, coil diameter and number of coils. -
Mechanical Engineering
Motor Power, Speed and Torque Calculator
Enter any two of power, torque and speed to get the third. Gearbox ratio and efficiency give output speed and torque. P = T × ω. -
Mechanical Engineering
Pulley Speed and Ratio Calculator
Driven speed and ratio from pulley diameters, or the pulley diameter needed for a target speed. With belt speed and slip allowance. -
Mechanical Engineering
Required Motor Power Calculator
Motor power needed to pull, lift or rotate a load, with drive efficiency and a service margin, plus the next standard motor rating. -
Mechanical Engineering
Shaft Combined Bending and Torsion Calculator
Required diameter or safety factor for a solid shaft under combined bending moment and torque. Von Mises and maximum shear stress criteria side by side. -
Mechanical Engineering
Shaft Torsion and Diameter Calculator
Required shaft diameter from torque, or shear stress and angle of twist for a given diameter. Solid and hollow shafts, τ = T × r / J. -
Mechanical Engineering
Spring Constant Calculator
Spring constant, force or deflection from Hooke's law. Equivalent rate of springs in series and parallel, and the rate of a helical spring from its wire and coil size. -
Mechanical Engineering
Spur Gear Module and Diameter Calculator
Pitch, tip, root and base diameters, circular pitch and centre distance of a spur gear from module and tooth count. Also module from the outside diameter.
Civil Engineering 33
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Civil Engineering
Bar Bending Schedule (BBS) Calculator
Cutting length, total length and weight per bar mark from diameter, shape and dimensions. Straight, L, U and stirrup shapes, bend deduction, CSV and print. -
Civil Engineering
Brick and Block Quantity Calculator
Number of bricks, concrete blocks or AAC blocks from wall and unit dimensions, with openings, joints, waste, units per square metre and joint mortar volume. -
Civil Engineering
Chemical Anchor Resin Volume and Cartridge Calculator
Finds the injection resin volume, the total with waste and the number of cartridges from hole diameter, rod diameter, embedment depth and quantity. -
Civil Engineering
Column and Beam Concrete Calculator
Concrete volume of rectangular or round columns and of beam webs below the slab, with the order quantity including waste and the weight. -
Civil Engineering
Concrete Mix Ratio Material Calculator
Approximate cement bags, sand, gravel and water for a concrete volume from a cement, sand and gravel volume ratio. Not a mix design. -
Civil Engineering
Concrete Volume Calculator
Concrete volume in cubic metres for slabs, footings and columns, with waste allowance, truck count and weight. -
Civil Engineering
Construction Markup and Profit Margin Calculator
Finds the bid price, profit, markup on cost and margin on price from direct cost and overhead, together with cost per square metre. -
Civil Engineering
Construction Material Takeoff Summary
Collects a material list into groups: waste per line, order quantity rounded to whole packs, amounts and group subtotals. CSV and print. -
Civil Engineering
Construction Progress and Payment Calculator
Finds physical progress, the value of work this period and the amount payable after tax and deductions from contract and completed quantities. CSV and print. -
Civil Engineering
Critical Path Method (CPM) Calculator
Finds project duration, the critical path, early and late times and total and free float from an activity list with durations and predecessors, and draws a bar chart. -
Civil Engineering
Excavation, Sloped Pit and Backfill Volume Calculator
Excavation volume of a vertical or sloped foundation pit and of a trench, with top dimensions, the extra volume caused by the slope and the backfill quantity. -
Civil Engineering
Facade Cladding and Panel Quantity Calculator
Finds the net cladding area, the order area with waste, the number of panels and the length of vertical support rails from facade size and openings. -
Civil Engineering
Floor Tile and Flooring Calculator
Finds the number of tiles or boards, boxes, grout and adhesive quantity and skirting length from the room area. -
Civil Engineering
Formwork Area Calculator
Formwork contact area in square metres for columns, beams, slabs, footings and walls. Slab depth is deducted on beams and edge forms are shown separately. -
Civil Engineering
Foundation Concrete Calculator
Concrete volume for pad, sloped pad, strip and raft foundations, with blinding concrete, base area and the order quantity including waste. -
Civil Engineering
Grout and Epoxy Fill Volume Calculator
Finds grout or epoxy volume in litres, material in kilograms and the number of bags for base plate grouting, anchor pockets or joint filling. -
Civil Engineering
Labour Productivity Calculator
Finds output per labour hour, labour hours per unit, daily crew output and efficiency against a target from work done, crew size and time worked. -
Civil Engineering
Mortar and Plaster Quantity Calculator
Approximate cement bags and sand from plaster area and thickness or from a mortar volume, plus the bag count for premixed plaster from its coverage rate. -
Civil Engineering
Paint Quantity Calculator
Finds how many litres and cans of paint you need from the wall and ceiling area, the number of coats and the spreading rate. -
Civil Engineering
Panel Fence Post and Panel Calculator
Finds the number of panels and posts and the concrete volume for post footings from fence length, gate openings and post spacing. -
Civil Engineering
Rebar Lap and Anchorage Length Calculator
Anchorage and lap length from concrete grade, steel and bar size using TS 500 or Eurocode 2 expressions, also as multiples of the bar diameter. Preliminary. -
Civil Engineering
Rebar Spacing and Quantity Calculator
Bar count from spacing, centre spacing and clear gap from bar count, and the largest spacing for a required steel area, with steel area per metre. -
Civil Engineering
Rebar Weight and Quantity Calculator
Rebar weight per metre, total length, kilograms and tonnes from rows of diameter, length and quantity, with a summary by diameter and CSV export. -
Civil Engineering
Roof Area and Pitch Calculator
Finds the surface area, rafter length, ridge height, pitch angle and slope percentage of a gable, mono pitch or hip roof from the building size and pitch. -
Civil Engineering
Roofing Sheet and Roof Tile Calculator
Finds the number of trapezoidal sheets, sandwich panels or corrugated sheets from cover width and laps, or the number of roof tiles from tiles per square metre. -
Civil Engineering
Scaffolding Area and Quantity Calculator
Finds the scaffold face area in m², the number of bays and lifts, and the frame and platform count from facade length and height. -
Civil Engineering
Soil Swell and Shrinkage Calculator
Convert between bank, loose and compacted soil volumes, find the cut needed for a fill, and derive swell and shrinkage percentages from densities. -
Civil Engineering
Stair Concrete Volume Calculator
Concrete volume of a straight reinforced concrete stair flight: waist slab, steps and landing shown separately, with slope length, pitch and order quantity. -
Civil Engineering
Stirrup Length and Quantity Calculator
Cutting length of a closed stirrup from the column or beam section, the number of stirrups with or without closely spaced end zones, total length and weight. -
Civil Engineering
Tile and Flooring Quantity Calculator
Tile count, boxes and grout quantity from area, tile size and waste allowance, plus box count and skirting pieces for laminate and parquet flooring. -
Civil Engineering
Truck Trips Calculator
Number of truck trips from cut volume, swell and body capacity, with an optional payload check and the job duration from cycle time and fleet size. -
Civil Engineering
Waterproofing Membrane Quantity Calculator
Finds the area to waterproof on a roof, foundation or wet room, the number of membrane rolls with laps, or the kilograms and packs of liquid membrane. -
Civil Engineering
Work Duration and Labour Hours Calculator
Finds total labour hours from quantity and hours per unit, then how many working days a crew needs or how many workers a target duration requires.
Electrical and Electronics 19
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Electrical and Electronics
Battery Capacity Calculator (Ah, Wh and Runtime)
Convert amp hours to watt hours, find how long a battery runs a load and the Ah needed for a wanted runtime. With efficiency and usable capacity. -
Electrical and Electronics
Battery Series and Parallel Connection Calculator
Total voltage, capacity (Ah) and energy (Wh) of cells or batteries in series and parallel. Series and parallel counts needed for a target voltage and capacity. -
Electrical and Electronics
Cable Size and Voltage Drop Calculator
Voltage drop, line resistance and power loss for copper and aluminium cables. Single phase, three phase and DC. Smallest standard size for a voltage drop limit. -
Electrical and Electronics
Electrical Power, Current and Voltage Calculator (Single and Three Phase)
Find power, current, voltage or power factor for single and three phase AC. Active, apparent and reactive power together. -
Electrical and Electronics
Generator Sizing Calculator (kVA)
Generator rating (kVA, kW) and current from connected load, demand factor and spare margin. Momentary kVA when the largest motor starts. All factors are user inputs. -
Electrical and Electronics
Inverter Size Calculator
Inverter rating from the load total, surge power when a motor load starts and the current drawn from the battery. Demand, margin and surge factors are user inputs. -
Electrical and Electronics
kW, kVA, HP and Amps Converter
Convert kW to kVA with power factor, kW to horsepower (metric and mechanical), and kW or kVA to amps. Single and three phase, with efficiency. -
Electrical and Electronics
LED Series Resistor Calculator
Series resistor for an LED, the next standard value up (E12, E24), the real current with that resistor and the power it dissipates. Works for LEDs in series too. -
Electrical and Electronics
Motor Starting Current Calculator
Approximate starting current of an induction motor for direct on line, star delta, autotransformer and current limited starting. The starting ratio comes from the datasheet. -
Electrical and Electronics
Ohm's Law Calculator
Enter any two of voltage, current and resistance to get the third and the power. V = I × R, P = V × I. -
Electrical and Electronics
Power Factor Correction Calculator (Required kvar)
Capacitor rating (kvar) needed to raise the power factor to a target. Current and apparent power before and after, plus capacitance. -
Electrical and Electronics
Resistor Color Code Calculator (4, 5 and 6 Band)
Reads a resistor value from its colour bands and finds the bands for a value. 4, 5 and 6 band resistors, tolerance range, temperature coefficient and a drawing. -
Electrical and Electronics
Series and Parallel Capacitor Calculator (Equivalent Capacitance)
Equivalent capacitance of up to 10 capacitors in series or in parallel. Stored charge and energy when a voltage is given. With worked steps. -
Electrical and Electronics
Series and Parallel Inductor Calculator (Equivalent Inductance)
Equivalent inductance of up to 10 inductors in series or in parallel. Stored energy when a current is given. Assumes no magnetic coupling between them. -
Electrical and Electronics
Series and Parallel Resistor Calculator (Equivalent Resistance)
Equivalent resistance of up to 10 resistors in series or in parallel. Total current and power when a voltage is given. With worked steps. -
Electrical and Electronics
Solar Panel Output Calculator (PV System Yield)
Installed power (kWp) and daily, monthly and annual yield from panel count and rating. Panels needed for a given consumption. Peak sun hours and efficiency are user inputs. -
Electrical and Electronics
Solar Panel String Sizing Calculator
String voltage, current and power. Cold open circuit and hot operating voltage are checked against the inverter limits. Maximum and minimum panels per string. -
Electrical and Electronics
UPS Sizing and Runtime Calculator
UPS rating (VA) from the load total, approximate runtime from a battery bank and the battery capacity for a wanted runtime. All factors are user inputs. -
Electrical and Electronics
Voltage Divider Calculator
Output voltage of a two resistor divider, loaded output, divider current and power. R1 or R2 for a wanted output with the nearest standard resistor.
Steel Structures and Statics 2
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Steel Structures and Statics
Beam Deflection Calculator
Support reactions, maximum moment and maximum deflection for simply supported and cantilever beams under point or distributed load, with shear, moment and deflection diagrams. -
Steel Structures and Statics
Moment of Inertia and Section Properties Calculator
Area, centroid, second moment of area (Ix, Iy), section modulus and radius of gyration for rectangle, box, circle, pipe, I, T, channel and angle sections.
Materials and Metallurgy 4
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Materials and Metallurgy
Linear Cutting Optimizer for Bars, Pipes and Profiles
Fits your cut list into stock lengths with minimum waste. Saw kerf, end trims, cutting sheet, reusable offcut list and CSV export. -
Materials and Metallurgy
Sheet and Plate Cutting Optimizer
Nests rectangular parts on sheets such as 1500×3000. Guillotine or free layout, kerf and edge margin, scaled drawings, offcut list, CSV and SVG export. -
Materials and Metallurgy
Steel Profile and Pipe Weight Calculator
Weight per metre, per piece and in total for IPE, HEA, HEB, pipe, hollow sections, angles, flat bar and plate. EN and DIN sizes, section drawing, project list, CSV and PDF. -
Materials and Metallurgy
Welded Wire Mesh Weight Calculator
Weight per square metre, per sheet and in total for welded wire mesh from bar diameter and spacing, with a lap allowance for ordering.
Manufacturing, CNC and Welding 1
Fluid Mechanics 15
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Fluid Mechanics
Bernoulli Equation Calculator
The Bernoulli equation between two points along a flow: find the pressure, velocity or elevation at the second point. Optional head loss, with worked steps. -
Fluid Mechanics
Flow Rate, Pipe Diameter and Velocity Calculator
Enter any two of flow rate, inside diameter and velocity to get the third. Q = v × A for a full circular pipe. -
Fluid Mechanics
Hazen-Williams Head Loss Calculator
Head loss, flow rate or required bore for water lines with the Hazen-Williams equation. Enter your own C factor and get a validity range check. -
Fluid Mechanics
Hydrostatic Pressure Calculator
Find pressure from liquid depth or liquid height from pressure with p = ρ × g × h. Gauge and absolute pressure in bar, kPa, metres of water and psi. -
Fluid Mechanics
Manning Open Channel Flow Calculator
Flow rate, velocity or normal depth from the Manning equation for rectangular, trapezoidal and partly full circular sections, with hydraulic radius and Froude number. -
Fluid Mechanics
NPSH Available Calculator (Suction Head Check)
Find the NPSH available at the pump suction and compare it with the manufacturer's NPSHr. Water vapour pressure is computed from temperature. -
Fluid Mechanics
Orifice Plate Flow Rate Calculator
Find flow rate from the pressure difference across an orifice plate, or the difference from the flow. Uses diameter ratio and discharge coefficient, for liquids. -
Fluid Mechanics
Pipe Pressure Drop Calculator (Darcy-Weisbach)
Enter flow, bore and length to get Reynolds number, flow regime, friction factor and pressure drop. Water properties follow from temperature. -
Fluid Mechanics
Pipeline Total Pressure Loss (Elbows, Valves, Fittings)
List straight pipe, elbows, tees, valves and entrance or exit items to get the loss of each, total pressure and head loss and the biggest contributor. K values are editable. -
Fluid Mechanics
Pump Operating Point and Efficiency Calculator
Enter pump curve points plus the static head and loss of the line to get the intersection with the system curve: duty flow, head, efficiency and shaft power, with a chart. -
Fluid Mechanics
Pump Power and Head Calculator
Hydraulic power, shaft power and motor input power from flow and head (or pressure rise), with head to pressure conversion. -
Fluid Mechanics
Static, Dynamic and Total Pressure Calculator
Get dynamic and total pressure from flow velocity, or work out velocity from the pressure difference read by a pitot tube. Preset densities for air and water. -
Fluid Mechanics
Tank Fill and Drain Time Calculator
Time for a tank to drain by gravity through a bottom orifice or outlet (Torricelli) and time to fill at a given flow rate. Cylindrical and rectangular tanks. -
Fluid Mechanics
Valve Kv and Cv Calculator
Find the required Kv and Cv from flow and pressure drop, or get flow and pressure drop from a known Kv. Includes Kv to Cv conversion, for liquids. -
Fluid Mechanics
Venturi Flow Rate Calculator
Find flow rate from the pressure difference between inlet and throat of a venturi meter, or the difference from the flow. Bernoulli plus continuity, with a discharge coefficient.
HVAC and Thermodynamics 14
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HVAC and Thermodynamics
Air Conditioner Cooling Load and BTU Calculator (Rough Sizing)
Rough cooling load from room area, ceiling height, occupants, equipment and glazing gains in W, kW and BTU/h. For preliminary sizing only. -
HVAC and Thermodynamics
Boiler Size Calculator (Preliminary)
Heating power from building heat loss or from area and unit load, plus instantaneous hot water power from flow rate. Rough preliminary boiler sizing. -
HVAC and Thermodynamics
Chiller Capacity and Chilled Water Flow Calculator (Preliminary)
Chiller capacity (kW, TR) from cooling load, chilled water flow from capacity and temperature difference, capacity from flow. Condenser heat and compressor power too. -
HVAC and Thermodynamics
Condensation and Mould Risk Calculator
Will a wall, window or pipe surface sweat at your room temperature and humidity? Enter the surface temperature or derive it from the U-value. -
HVAC and Thermodynamics
Dehumidification Capacity Calculator
From airflow and the temperature and humidity of entering and leaving air, find water removed (kg/h) and the total, sensible and latent cooling load. -
HVAC and Thermodynamics
Dew Point and Relative Humidity Calculator
Find the dew point from temperature and relative humidity, or relative humidity from temperature and dew point. Absolute humidity and vapour pressure included. -
HVAC and Thermodynamics
Duct Pressure Drop and Duct Size Calculator
Velocity, friction rate (Pa/m) and pressure drop in round or rectangular air ducts. Duct diameter and section from a target velocity or equal friction. -
HVAC and Thermodynamics
Fan Power and Static Pressure Calculator
From airflow, duct and equipment pressure losses and fan efficiency, find fan pressure, air power, shaft power, motor input power and specific fan power. -
HVAC and Thermodynamics
Mixed Air Temperature and Enthalpy Calculator
Find the temperature, relative humidity, humidity ratio and enthalpy when two airstreams such as outdoor and return air mix. By mass and energy balance. -
HVAC and Thermodynamics
Psychrometric Calculator: Moist Air Properties
Enter dry-bulb temperature plus relative humidity, wet bulb, dew point or humidity ratio to get enthalpy, humidity ratio, specific volume and the rest. Altitude supported. -
HVAC and Thermodynamics
Radiator Output Calculator (Preliminary)
Correct catalogue output to your own flow, return and room temperatures: what a radiator gives at low temperature and how much length or how many sections you need. -
HVAC and Thermodynamics
Room Heating Load and Heat Loss Calculator (Preliminary)
Estimate a room's heat loss and required heating power from wall, window, roof and floor areas with their U-values and the indoor and outdoor temperatures. -
HVAC and Thermodynamics
Underfloor Heating Pipe Length Calculator
From laid area and pipe spacing find total pipe length, number of circuits, length per circuit and water volume in the pipe. Circuit flow rate optional. -
HVAC and Thermodynamics
Ventilation Rate and Air Changes per Hour (ACH) Calculator
Airflow from room volume and air changes per hour, ACH from airflow, fresh air from occupancy and floor area, and the flow needed to hold a CO₂ limit.