About PipeVolume
PipeVolume is a free set of calculators for working out how much a pipe holds — in gallons, litres, cubic feet, cubic metres, barrels and more — from its internal diameter and length.
What this site does
Every tool here is built on one piece of geometry: the internal volume of a cylinder. Where the site earns its keep is in the details around that formula — loading the correct bore for standard pipe so you never confuse nominal size with the real inside diameter, converting a single calculation into every common unit at once, and adding the things people actually need next, such as the weight of the water and the time to fill or drain a line.
The dimensions behind the tools
Accurate volume depends on accurate bores. The built-in pipe dimensions come from the standards the trades use: ASME B36.10 for steel and PVC pipe schedules, ASTM B88 for copper tube types K, L and M, and ASTM F876 for PEX. HDPE bores are derived from the IPS outside diameter and the dimension ratio (DR). Nominal sizes are treated as labels and converted to the true bore before any calculation.
How we think about accuracy
The results are exact for a round, uniform, full pipe to the precision of the bore you enter. We are explicit about the limits too: fittings and bends add a little volume, part-full gravity lines need a fill level, gases need a pressure correction for the actual quantity, and safety-critical work should always be confirmed against manufacturer data and the relevant code. A good calculator tells you where its answer stops being exact.
Who it is for
The tools are built to serve very different people from one calculation. Homeowners and DIY users work out the water in a radiant loop, a garden line or a pool return. Plumbers, HVAC technicians and pipefitters confirm capacity, weight and fill time on site before charging a system. Irrigation, pool and facility operators plan top-ups, flushing and disinfection. Engineers and estimators pull per-foot capacity into take-offs, size expansion tanks, and reconcile line fill against tank and tanker volumes. On the industrial side the same geometry handles fire-sprinkler flushing volumes, chemical-transfer line contents and pipeline line fill.
Our accuracy commitment
Every worked example on the site is calculated, not estimated, and checked against the underlying standard before publishing. Where a result depends on an assumption — full versus part-full, which schedule, which dimension ratio — the page says so and lets you change it. When we find an error we correct it and welcome reports; a calculator is only worth using if its numbers are right.
Free to use
The calculators are free and run entirely in your browser. Recent calculations are stored on your own device so you can reopen them, and nothing about your calculations is sent anywhere. If a calculation you need is missing, the guides section is built to grow — the aim is to cover the volume questions that keep coming up in real work.