Pipe volume and fill time calculator

Calculate pipe volume in gallons or liters from inside diameter and length, and the time to fill it at a given flow.

What this means

System volume tells you how much water, glycol or treatment chemical a loop needs and how long a fill or flush takes. Presets use typical inside diameters; actual ID varies by pipe type and manufacturer.

Formula used

  • Volume (ft³) = π × (ID ÷ 2)² × length
  • Gallons = ft³ × 7.48
  • Fill time (min) = gallons ÷ GPM

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Estimates based on your inputs. Always verify against the manufacturer's data and the codes that apply where you work.

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