Pipe Schedule Chart (NPS 1/8 to 24)

Steel pipe schedule chart for NPS 1/8 to 24: Sch 10, 40, 80 and 160 wall thickness, OD, ID and theoretical kg/m. Labelled drawing, ASME B36.10M.

For preliminary reference and dimensional comparison. Tolerances, pressure capacity and joint safety are not assessed. Confirm against the applicable standard before manufacture or final selection.

Dimension drawing and symbols

D: Outside diameter mm
t: Wall thickness mm
d_i: Calculated inside diameter mm

NPS is a nominal size, not the outside diameter. The STD badge marks a wall equal to Sch 40 and the XS badge a wall equal to Sch 80, shown only for the sizes where that equality holds.

Visible rows: 24

Wall thickness

Pipe schedule chart, wall thickness
NPS	DODmm	Sch 10	Sch 40	Sch 80	Sch 160
		Wall thickness t, mm
1/8	10.3	1.24	1.73STD	2.41XS	no value
1/4	13.7	1.65	2.24STD	3.02XS	no value
3/8	17.1	1.65	2.31STD	3.20XS	no value
1/2	21.3	2.11	2.77STD	3.73XS	4.78
3/4	26.7	2.11	2.87STD	3.91XS	5.56
1	33.4	2.77	3.38STD	4.55XS	6.35
1 1/4	42.2	2.77	3.56STD	4.85XS	6.35
1 1/2	48.3	2.77	3.68STD	5.08XS	7.14
2	60.3	2.77	3.91STD	5.54XS	8.74
2 1/2	73.0	3.05	5.16STD	7.01XS	9.53
3	88.9	3.05	5.49STD	7.62XS	11.13
3 1/2	101.6	3.05	5.74STD	8.08XS	no value
4	114.3	3.05	6.02STD	8.56XS	13.49
5	141.3	3.40	6.55STD	9.53XS	15.88
6	168.3	3.40	7.11STD	10.97XS	18.26
8	219.1	3.76	8.18STD	12.70XS	23.01
10	273.0	4.19	9.27STD	15.09	28.58
12	323.8	4.57	10.31	17.48	33.32
14	355.6	6.35	11.13	19.05	35.71
16	406.4	6.35	12.70	21.44	40.49
18	457.0	6.35	14.27	23.83	45.24
20	508.0	6.35	15.09	26.19	50.01
22	559.0	6.35	no value	28.58	53.98
24	610.0	6.35	17.48	30.96	59.54

Inside diameter

Inside diameter
NPS	DODmm	Sch 10	Sch 40	Sch 80	Sch 160
		Calculated inside diameter d_i, mm
1/8	10.3	7.82	6.84	5.48	no value
1/4	13.7	10.40	9.22	7.66	no value
3/8	17.1	13.80	12.48	10.70	no value
1/2	21.3	17.08	15.76	13.84	11.74
3/4	26.7	22.48	20.96	18.88	15.58
1	33.4	27.86	26.64	24.30	20.70
1 1/4	42.2	36.66	35.08	32.50	29.50
1 1/2	48.3	42.76	40.94	38.14	34.02
2	60.3	54.76	52.48	49.22	42.82
2 1/2	73.0	66.90	62.68	58.98	53.94
3	88.9	82.80	77.92	73.66	66.64
3 1/2	101.6	95.50	90.12	85.44	no value
4	114.3	108.20	102.26	97.18	87.32
5	141.3	134.50	128.20	122.24	109.54
6	168.3	161.50	154.08	146.36	131.78
8	219.1	211.58	202.74	193.70	173.08
10	273.0	264.62	254.46	242.82	215.84
12	323.8	314.66	303.18	288.84	257.16
14	355.6	342.90	333.34	317.50	284.18
16	406.4	393.70	381.00	363.52	325.42
18	457.0	444.30	428.46	409.34	366.52
20	508.0	495.30	477.82	455.62	407.98
22	559.0	546.30	no value	501.84	451.04
24	610.0	597.30	575.04	548.08	490.92

Mass per metre

Mass per metre
NPS	DODmm	Sch 10	Sch 40	Sch 80	Sch 160
		Theoretical mass per metre, kg/m
1/8	10.3	0.277	0.366	0.469	no value
1/4	13.7	0.490	0.633	0.795	no value
3/8	17.1	0.629	0.843	1.097	no value
1/2	21.3	0.999	1.266	1.616	1.947
3/4	26.7	1.280	1.687	2.198	2.899
1	33.4	2.092	2.502	3.237	4.236
1 1/4	42.2	2.694	3.392	4.467	5.614
1 1/2	48.3	3.110	4.049	5.415	7.248
2	60.3	3.930	5.437	7.482	11.113
2 1/2	73.0	5.261	8.633	11.408	14.917
3	88.9	6.457	11.293	15.274	21.347
3 1/2	101.6	7.413	13.570	18.635	no value
4	114.3	8.368	16.075	22.322	33.538
5	141.3	11.563	21.767	30.969	49.118
6	168.3	13.827	28.264	42.564	67.566
8	219.1	19.968	42.549	64.645	111.273
10	273.0	27.777	60.292	95.979	172.274
12	323.8	35.978	79.708	132.049	238.694
14	355.6	54.693	94.551	158.112	281.715
16	406.4	62.648	123.307	203.545	365.377
18	457.0	70.572	155.805	254.567	459.395
20	508.0	78.559	183.433	311.194	564.849
22	559.0	86.545	no value	373.854	672.297
24	610.0	94.532	255.425	442.109	808.266

Quick answers

NPS 1/2 Sch 40 pipe: OD 21.3 mm, wall thickness 2.77 mm, ID 15.76 mm, theoretical mass 1.266 kg/m. View in table
NPS 3/4 Sch 40 pipe: OD 26.7 mm, wall thickness 2.87 mm, ID 20.96 mm, theoretical mass 1.687 kg/m. View in table
NPS 1 Sch 40 pipe: OD 33.4 mm, wall thickness 3.38 mm, ID 26.64 mm, theoretical mass 2.502 kg/m. View in table
NPS 2 Sch 40 pipe: OD 60.3 mm, wall thickness 3.91 mm, ID 52.48 mm, theoretical mass 5.437 kg/m. View in table
NPS 3 Sch 40 pipe: OD 88.9 mm, wall thickness 5.49 mm, ID 77.92 mm, theoretical mass 11.293 kg/m. View in table
NPS 4 Sch 40 pipe: OD 114.3 mm, wall thickness 6.02 mm, ID 102.26 mm, theoretical mass 16.075 kg/m. View in table
NPS 6 Sch 40 pipe: OD 168.3 mm, wall thickness 7.11 mm, ID 154.08 mm, theoretical mass 28.264 kg/m. View in table
NPS 8 Sch 40 pipe: OD 219.1 mm, wall thickness 8.18 mm, ID 202.74 mm, theoretical mass 42.549 kg/m. View in table

Conditions and notes

Nominal dimension series referenced to ASME B36.10M:2018. Assumed carbon steel density is 7850 kg/m³. Nominal geometry is used.

Di = D − 2t. Mass per length = 7850 × π × t × (D − t), with D and t in metres. Coatings and tolerances are excluded.
STD equals Sch 40 only up to and including NPS 10. XS equals Sch 80 only up to and including NPS 8. They are not universal synonyms.
Blank cells are values not published because this pilot could not verify them against two numeric publishers. A blank Sch 160 cell at a small size does not mean the standard lacks that dimension.
Published nominal dimensions use their own rounding conventions. Do not use NPS or outside diameter as the flow diameter.
ASME B36.10:2022 changed SI outside diameter rounding. This table uses the 2018 series. Confirm the contractual standard before switching editions or dimension series.
CSV download is unavailable because the sources do not establish permission for reuse.

Sch 10, 40, 80 and 160 wall thicknesses from NPS 1/8 to 24. Inside diameter and theoretical mass per length are calculated from geometry.

Sources

This table is for preliminary reference. Check the applicable standard and product conditions before use.

Source 1. Undated catalogue referencing ASME B36.10. Accessed: 2026-10-16
Source 2. Undated numerical table. The referenced edition is stated in the conditions.. Accessed: 2026-10-16
Source 3. Undated numerical table. The referenced edition is stated in the conditions.. Accessed: 2026-10-16
Source 4. Undated table referencing ASME B36.10 and B36.19. Accessed: 2026-10-16

Data version: 2026-10-16