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Pipe Volume Calculator

Estimate pipe volume in gallons and liters.

Pipe volume equals π × radius² × length. In practical units, a 1 inch ID pipe holds about 0.041 gallons per foot, ¾ inch about 0.023, 2 inch about 0.163, and 4 inch about 0.653 gallons per foot. Multiply by total run length for system volume. Enter your pipe diameter and length for gallons, liters and fill weight.

How does the pipe volume calculator work?

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

What else do people ask about this calculator?

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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