Pipe Volume Calculator
Enter a pipe's inside diameter and length to calculate its volume in gallons, liters, and cubic feet — handy for estimating water capacity, flushing, and chemical dosing.
Based on V = π × r² × length, using the pipe's inside diameter. Results are estimates for a full pipe.
How the pipe volume calculation works
A pipe is a cylinder, so its volume is the cross-sectional area times the length: V = π × r² × L. The radius is half the inside diameter. This tool converts the result from cubic feet into US gallons (about 7.48 gallons per cubic foot) and liters.
For plumbers and contractors, knowing pipe volume helps with estimating water capacity, sizing flushes, dosing chemicals, and planning drain-down or fill times accurately.
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