Pipe Volume Calculator

Enter inner diameter and pipe length to get internal volume in liters, US gallons, and cubic feet.

Pipe Dimensions

Common nominal pipe inner diameters

½″ NPS → 0.622″¾″ NPS → 0.824″ 1″ NPS → 1.049″1¼″ NPS → 1.380″ 1½″ NPS → 1.610″2″ NPS → 2.067″ 3″ NPS → 3.068″4″ NPS → 4.026″ 6″ NPS → 6.065″8″ NPS → 7.981″

Enter diameter and length, then click Calculate.

Copied!

Summary

Enter inner diameter and pipe length to get internal volume in liters, US gallons, and cubic feet.

How it works

  1. Enter the pipe inner diameter and pipe length.
  2. Select units for each measurement (inches, feet, millimeters, or meters).
  3. The calculator applies V = π × (d/2)² × L to get volume in cubic inches or cubic millimeters.
  4. Results are converted to liters, US gallons, and cubic feet.

Use cases

  • Estimate water volume needed to fill or flush a piping system.
  • Size water heaters or pressure tanks for residential plumbing.
  • Calculate fluid inventory in industrial pipe runs.
  • Plan chemical dosing volumes for treatment systems.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu