Pipe Volume Calculator
Estimate water or material volume inside a circular pipe from inside diameter and length. Use it for disinfection volume, hydrostatic test water, or comparing pipe displacement.
Enter your values, then press Calculate.
How to calculate
Enter the inside diameter (not OD unless the wall is negligible) and the pipe length. Diameter is usually inches on the spec sheet; length is usually feet.
Formula
Radius (ft) = ID / 2. Volume (ft³) = π × r² × length. Gallons = ft³ × 7.48051948. Cubic yards = ft³ ÷ 27.
Common use cases
- Chlorination / disinfection volume
- Hydrostatic test water
- Pipe displacement vs backfill
- Comparing 8 in vs 12 in ID
Worked example
Example: 12 in ID × 100 ft
1. Cross-section area
π × (1 / 2)² = 0.7854 ft²
2. Volume
0.7854 × 100 = 78.5398 ft³
3. Gallons
78.5398 × 7.48051948 = 587.5186 gal
Related calculators
- Pipe Slope CalculatorConvert elevation drop and run into percent grade, ratio, and inches per foot.
- Bedding CalculatorEstimate pipe bedding cubic yards from length, width, and depth.
- Backfill CalculatorEstimate trench backfill cubic yards after subtracting pipe displacement.
- Percent Grade CalculatorConvert rise and run into percent grade, slope ratio, and feet per 100 feet.
FAQ
ID or OD?
Liquid volume uses inside diameter. For trench displacement / backfill deduction, the backfill calculator wants outside diameter.
Is the pipe assumed full?
Yes. The result is the full circular prism. Partial flow or slope is not applied.
Disclaimer
These calculators are estimating tools for planning and field checks. They are not a substitute for approved plans, specifications, licensed professional engineering, or governing standards. Confirm densities, waste factors, and yields with your supplier and project documents.