Pipe Volume Calculator

Find pipe volume, capacity in US gallons and litres, and liquid weight from outside diameter, wall thickness, and length. Continue on pump sizing when you need flow and head for the line.

Pipe inputs

Pipe preset

Outside diameter (OD)

Wall thickness

Pipe length

Unit system

Liquid

About this calculator

Volume is the inside cross-section area times the pipe length, using the inside diameter (OD minus twice the wall). Capacity is reported in US gallons and litres, and liquid weight uses the density you select. Continue on the power calculators hub.

Result

Planning estimate. Confirm the pipe schedule and wall thickness before you order or fill.

Assumptions: a circular pipe of constant inside diameter, no fittings or valves, and the liquid density you selected. Capacity ignores air pockets and free surface effects. This screen does not use power factor.

Continue Your Calculation

Know the pipe volume? Continue in pump sizing to get flow, head, and shaft power for this line.

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Schedule 40 steel pipe capacity chart

NPS	OD (in)	Wall (in)	ID (in)	US gal per ft	Litres per m
1/2	0.840	0.109	0.622	0.0158	0.196
3/4	1.050	0.113	0.824	0.0277	0.344
1	1.315	0.133	1.049	0.0449	0.557
1-1/4	1.660	0.140	1.380	0.0777	0.965
1-1/2	1.900	0.145	1.610	0.1058	1.313
2	2.375	0.154	2.067	0.1743	2.165
3	3.500	0.216	3.068	0.3841	4.769
4	4.500	0.237	4.026	0.6614	8.212

Capacity per foot or per metre, using the inside diameter and the same areas as the calculator. Nominal pipe size is not the outside diameter, so always use the OD and wall for the schedule you have.

Formula

Volume = (pi / 4) × ID² × Length, where ID is the inside diameter (OD − 2 × wall). Cross-section area uses the inside diameter, so wall thickness matters: a 2 in Schedule 40 steel pipe has an OD of 2.375 in and a 0.154 in wall, giving an ID of 2.067 in. Over 10 ft that is (pi / 4) × 2.067² / 144 × 10 = 0.233 ft³, about 1.74 US gallons or 6.60 litres.

Worked example

2 in Schedule 40 steel, 10 ft long: inside area 3.355 in², volume 0.233 ft³ (6.60 litres), capacity 1.743 US gallons, and with water at 62.4 lb/ft³ the liquid weighs about 14.5 lb.

Same pipe in 1 in Schedule 40 steel: ID 1.049 in, so 10 ft holds only 0.0600 ft³ (0.449 US gal, 1.70 litres) — about 26% of the 2 in line, because capacity scales with the square of the inside diameter.

FAQ

How do you calculate pipe volume?

Multiply the inside cross-section area by the pipe length. The inside area is pi divided by 4 times the inside diameter squared. Use the inside diameter, not the outside diameter, so subtract twice the wall thickness from the outside diameter first.

How many litres are in 1 metre of pipe?

For a 50 mm inside diameter pipe, 1 metre holds about 1.96 litres. Capacity scales with the square of the inside diameter, so doubling the inside diameter roughly quadruples the litres per metre.

What is the volume of a 2 inch Schedule 40 steel pipe?

A 2 in Schedule 40 steel pipe has an outside diameter of 2.375 in and a 0.154 in wall, so the inside diameter is 2.067 in. Per foot that is about 0.0233 cubic feet, or 0.174 US gallons (2.16 litres per metre).

Does pipe volume use the inside or outside diameter?

Always the inside diameter. The wall does not hold liquid, so using the outside diameter overstates volume. For a 2 in Schedule 40 pipe the outside diameter is 2.375 in against an inside diameter of 2.067 in, about 32% more area than the pipe actually holds.

How many gallons does a pipe hold?

Convert the volume to US gallons by multiplying cubic feet by 7.4805, or divide cubic feet by 0.13368. For metric pipe, multiply cubic metres by 1,000 for litres.

Does this calculator handle steel, copper, and PVC?

Yes, as long as you enter that pipe's outside diameter and wall thickness. The preset list uses Schedule 40 steel. Copper and PVC have different walls for the same nominal size, so enter their values directly.