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Pipe Volume Calculator

Free online pipe volume calculator to calculate internal volume, capacity, and water weight for circular pipes. Calculate based on diameter and length for plumbing and engineering.

The Pipe Volume Calculator helps you calculate the internal volume and capacity of circular pipes and tubes. Enter pipe diameter and length to determine volume in liters, gallons, and cubic meters, plus the weight of water or fluid contained.
Pipe Dimensions
Fluid Settings (Optional)
Pipe Cross-SectionDLengthVolume

What is Pipe Volume?

Pipe volume (also called pipe capacity) is the amount of fluid that a pipe can contain, calculated as the internal cross-sectional area multiplied by the pipe length. This calculation is essential for determining how much liquid or gas a piping system can hold, which is important for system filling time, drainage calculations, chemical dosing, thermal expansion considerations, and understanding system capacity. The volume depends only on the internal diameter and length of the pipe.

Pipe Volume Formulas

1. Volume = π × r² × L = π × (D/2)² × L

Where: r = radius, D = internal diameter, L = length

2. Fluid Weight = Volume × Density

3. Pipe Material Volume = π × [(D₂/2)² - (D₁/2)²] × L

Common Pipe Sizes & Volumes

½" pipe (15mm): ~0.18 L per meter

¾" pipe (20mm): ~0.31 L per meter

1" pipe (25mm): ~0.49 L per meter

1½" pipe (40mm): ~1.26 L per meter

2" pipe (50mm): ~1.96 L per meter

3" pipe (75mm): ~4.42 L per meter

4" pipe (100mm): ~7.85 L per meter

Applications

  • Plumbing: System capacity, filling time calculations
  • HVAC: Hydronic systems, glycol volume for antifreeze
  • Chemical processing: Reactant volumes, batch sizing
  • Water treatment: Tank sizing, retention time
  • Fire protection: Standpipe volume, system priming
  • Heating: Expansion tank sizing, system volume
  • Oil & Gas: Pipeline inventory, drainage calculations

Tips for Pipe Volume Calculations

  • Use inner diameter for volume calculations, not outer diameter
  • Account for fittings and valves - they add to total system volume
  • For heating systems, accurate volume determines expansion tank size
  • Consider thermal expansion of contained fluids
  • Pipe schedule affects wall thickness and thus internal diameter
  • Large diameter changes have dramatic effect on volume (diameter squared relationship)
  • System volume affects filling time, chemical dosing rates, and purging requirements
See also
ENGINEERING CALCULATORS
WUTOOLS