Steel Pipe Weight Calculation Formula

The theoretical weight of steel pipe is calculated from its outer diameter and wall thickness. The formula is derived from the cross-sectional area of the pipe wall multiplied by the density of carbon steel (approximately 7850 kg/m³ or 490 lb/ft³).

Metric Formula (SI Units)

W (kg/m) = (OD - WT) x WT x 0.02466

Where OD = Outer Diameter (mm), WT = Wall Thickness (mm), 0.02466 = density factor (derived from steel density 7850 kg/m³ x pi / 1000).

Imperial Formula (US Units)

W (lb/ft) = (OD - WT) x WT x 10.69

Where OD = Outer Diameter (inches), WT = Wall Thickness (inches).

Example Calculation

For a 12-inch (323.9 mm OD) Schedule 40 pipe with wall thickness 9.53 mm:

Metric: W = (323.9 - 9.53) x 9.53 x 0.02466 = 73.88 kg/m
Imperial: W = (12.75 - 0.375) x 0.375 x 10.69 = 49.56 lb/ft

Standard Pipe Schedule Weight Table (API 5L / ASTM A53 / A106)

Common carbon steel pipe sizes with calculated weights for standard schedules. Weights are theoretical; actual production weights vary within the tolerance limits of the applicable specification (typically +/-10% for most sizes, +/-12.5% for light-wall pipe).

NPS	OD (inch)	OD (mm)	SCH 10	SCH 20	SCH 30	SCH 40 / STD	SCH 60	SCH 80 / XS	SCH 100	SCH 120	SCH 140	SCH 160	XXS
1/2"	0.840	21.3	0.67	—	—	1.27	—	1.62	—	—	—	2.28	3.69
3/4"	1.050	26.7	0.86	—	—	1.69	—	2.20	—	—	—	3.03	4.48
1"	1.315	33.4	1.14	—	—	2.50	—	3.24	—	—	—	4.49	6.63
1-1/2"	1.900	48.3	1.74	—	—	4.05	—	5.41	—	—	—	7.25	10.62
2"	2.375	60.3	2.38	—	—	5.44	—	7.48	—	—	—	10.68	13.86
3"	3.500	88.9	4.27	—	—	11.29	—	15.27	—	—	—	22.53	26.76
4"	4.500	114.3	6.77	—	—	16.07	—	22.32	—	25.82	—	32.60	39.47
6"	6.625	168.3	12.89	—	—	28.26	—	42.56	—	54.20	—	64.87	78.84
8"	8.625	219.1	19.54	23.17	27.31	42.55	51.08	64.46	72.06	80.87	89.28	97.94	112.99
10"	10.750	273.1	24.82	32.52	38.57	60.31	72.39	92.05	102.63	119.79	134.61	150.47	174.55
12"	12.750	323.9	29.78	39.58	48.59	73.88	91.80	118.11	131.57	158.83	176.93	198.78	237.15
14"	14.000	355.6	32.77	43.79	55.03	81.33	104.61	133.21	151.14	179.76	202.18	229.04	—
16"	16.000	406.4	37.55	50.30	63.29	93.27	120.17	153.43	174.25	208.19	234.07	265.92	—
18"	18.000	457.2	42.33	56.80	71.57	105.17	135.74	173.76	197.07	236.75	266.14	303.25	—
20"	20.000	508.0	47.10	63.32	79.85	117.15	151.31	194.10	220.08	264.90	297.92	340.49	—
24"	24.000	609.6	56.66	76.34	96.42	140.79	192.82	235.05	271.94	322.28	365.65	423.96	—

Weights shown in kg/m. For lb/ft, multiply kg/m by 0.672. Values are theoretical based on nominal dimensions. Standard weight (STD) is equivalent to SCH 40 for NPS 1/8 through 10; Extra Strong (XS) is equivalent to SCH 80 for NPS 1/8 through 8. Double Extra Strong (XXS) has no schedule equivalent.

Large Diameter Pipe Weight Examples (API 5L LSAW / SSAW)

OD (inch)	OD (mm)	WT 6 mm	WT 8 mm	WT 10 mm	WT 12 mm	WT 14 mm	WT 16 mm	WT 20 mm	WT 25 mm
20"	508	74.3	98.7	122.9	146.9	171.0	194.9	242.3	301.6
24"	610	89.5	119.0	147.8	176.4	204.8	233.5	290.4	361.5
28"	711	104.4	138.9	172.7	206.3	239.8	273.0	339.7	423.8
30"	762	111.9	148.9	185.8	222.0	258.5	294.9	367.4	458.4
32"	813	119.6	159.1	198.2	237.2	276.5	315.4	393.1	490.6
36"	914	134.5	179.0	223.2	267.3	311.2	355.0	442.8	553.5
40"	1016	149.5	199.0	248.3	297.4	346.3	395.1	492.6	615.6
48"	1219	179.5	239.0	298.4	357.6	416.7	475.6	593.2	742.1

Weights shown in kg/m. Formula: W = (OD - WT) x WT x 0.02466. For imperial (lb/ft), multiply by 0.672.

Important Note on Weight Tolerances: Actual pipe weights may vary from theoretical values due to mill tolerances on OD and WT. API 5L specifies a wall thickness tolerance of +/-12.5% for most sizes (up to +/-15% for some seamless pipe), which translates to a weight variation of approximately +/-10%. For structural applications, ASTM A252 typically specifies +10%/-3.5% on weight. Always confirm actual weight with the mill test certificate (MTC) for your specific order.

Steel Pipe Weight Chart & Calculator Guide