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Pipe Volume Calculator

Calculates the internal volume of any pipe from diameter and length

Inside diameter of the pipe in inches

Total length of the pipe in feet

Volume (cu in)

Enter pipe dimensions to calculate volume

Volume (cu ft)

Volume in cubic feet

Volume (gallons)

Volume in US gallons

Volume (liters)

Volume in liters

Frequently Asked Questions

How do I calculate the volume of a pipe?

Use the cylinder volume formula: V = pi x r squared x length, where r is the inner radius. Make sure to use the inner diameter, not the outer diameter, since wall thickness reduces the usable volume inside the pipe.

Why do I need to know pipe volume?

Knowing pipe volume helps with flushing water lines, calculating chemical treatment doses, estimating drain-down volumes, and sizing expansion tanks. Plumbers and HVAC technicians use it regularly for system design and maintenance.

What is the difference between nominal and actual pipe diameter?

Nominal pipe size (NPS) is a label, not an exact measurement. A 1-inch nominal pipe does not have a 1-inch inner diameter. Actual inner diameters vary by pipe material and schedule. Always measure the actual inner diameter for accurate volume calculations.

How many gallons of water are in 100 feet of 1-inch pipe?

A 1-inch Schedule 40 PVC pipe has an inner diameter of about 1.049 inches. The volume of 100 feet is approximately 4.08 gallons. Copper pipe of the same nominal size has a slightly different inner diameter and holds about 4.43 gallons.