Calculate water volume and weight
This calculator determines the volume of water that a pipe can hold based on its internal diameter and length.
Formula: Volume = π × r² × L
Where r = radius (diameter ÷ 2), L = length
Weight of water: 1 gallon weighs 8.34 pounds at room temperature. This matters for structural calculations and pump sizing.
Common applications:
• System capacity planning
• Drain time calculations
• Chemical treatment dosing
• Thermal expansion estimates
• Water heater recovery time
Important notes:
• Use inside diameter (ID), not nominal size
• 1 gallon = 231 cubic inches
• 1 cubic foot = 7.48 gallons
• Cold water is slightly denser than hot
How to use: Select your pipe size (or enter custom diameter), enter length, and get instant results for volume in gallons, liters, cubic feet, and total weight.