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Pipe Volume Calculator

Estimate pipe volume in gallons and liters.

How the pipe volume calculator works

Volume = π × r² × length. Convert length to inches, then divide the resulting cubic inches by 231 to get gallons.

Frequently asked questions

How many gallons in a 100 ft pipe?

A 1 in ID pipe × 100 ft holds ~4.1 gallons. A 2 in pipe × 100 ft holds ~16.3 gallons.

What's the difference between ID and OD?

Use inside diameter (ID) for volume — the wall thickness doesn't hold water.

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