Free forever

Pipe Volume Calculator

Estimate pipe volume in gallons and liters.

Use this pipe volume calculator to estimate how much liquid a pipe holds in gallons and liters. Enter the pipe’s inside diameter (ID) and length to calculate its capacity. The calculation uses the cylinder volume formula and converts the result from cubic inches to gallons.

in
ft

Volume

2.04

gallons

Volume

7.72

liters

Volume

471

in³

Save this project

Sign in to save calculations to your dashboard.

Download your PDF report & project guide

Your results and inputs, a printable shopping list, a step-by-step guide and pro tips — in one PDF.

Recommended tools & materials

Handy picks for this project on Amazon.

As an Amazon Associate, MaterialCalc earns from qualifying purchases.

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.

Which related calculators should I use next?

All calculators

Complete Your Plumbing Project

These practical tools and supplies can help you measure, assemble, and seal your pipe installation.

Paid links: as an Amazon Associate, MaterialCalc earns from qualifying purchases.