Pipe Volume Calculator
Get the internal (bore) volume of a pipe run from its inside diameter and length — for line fill volume, purge/flush volume, chemical dosing, or pigging and hydrotest water volume estimates.
Pipe Inputs
Formula
Worked example
8″ NPS Schedule 40 pipeline, 250 m long, full of water.
| Step | Calculation |
|---|---|
| ID (8″ Sch 40) | 219.1 − 2×8.18 = 202.74 mm = 0.20274 m |
| Volume | (π/4)(0.20274²)(250) = 8.071 m³ |
| Litres | 8.071 × 1000 = 8,071 L |
| US gallons | 8.071 × 264.172 = 2,132 gal |
| Water weight (ρ=1000 kg/m³) | 8.071 × 1000 = 8,071 kg |
Frequently asked questions
Does this account for fittings, valves or vessel volume?
No — this is straight-run pipe bore volume only (π/4 × ID² × L). For a full system fill volume, add fitting/valve internal volumes and any in-line equipment volume separately.
Why use inside diameter instead of nominal size?
Inside diameter, not NPS, determines the actual bore volume, and it changes with schedule — an 8″ Sch 40 pipe (ID 202.7 mm) holds noticeably more than an 8″ Sch 80 pipe (ID 193.7 mm) over the same length.
What is this useful for in plant engineering?
Common uses include hydrotest water volume, chemical/nitrogen purge volume, pigging displacement volume, batch transfer line hold-up, and line-fill weight for pipe support and stress calculations.