Pipe Volume Calculator
Calculator
Knowing the internal volume of a pipe is essential for system fill volumes, purge time calculations, water hammer analysis, and chemical dosing. Enter the internal diameter and pipe length to get the volume in liters, cubic meters, and US gallons.
Formula
Formula
V = π × (d/2)² × L
V is volume in cubic meters. d is internal diameter in meters (entered in mm, converted by dividing by 1,000). L is length in meters. The result is then converted: 1 m³ = 1,000 L; 1 L = 0.264172 US gallons.
Worked example
A 50 mm internal diameter pipe, 10 m long. Find the fill volume.
- 1.Radius r = 50 mm / 2 = 25 mm = 0.025 m
- 2.V = π × (0.025)² × 10 = π × 0.000625 × 10 = 0.019635 m³
- 3.V in liters = 0.019635 × 1,000 = 19.635 L
- 4.V in US gallons = 19.635 × 0.264172 = 5.186 gal
The pipe holds approximately 19.6 L (5.19 US gallons).
Assumptions and limitations
- Uses internal (bore) diameter, not nominal or outer diameter.
- Diameter is entered in mm; length in meters.
- Assumes a perfectly circular cross-section (no deformation).
- Does not account for fittings, valves, or expansion joints.
Frequently asked questions
Related tools and guides
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Convert liters, gallons, cubic meters, and more.
Imperial to metric volume conversion.