Volume = π × radius² × length, using the inside diameter.
Enter realistic numbers from the property, equipment, job record, or company reports. Small input changes can produce large differences, so compare the estimate with actual performance.
Practical answers
Should pipe volume use inside or outside diameter?
Use the inside diameter because liquid occupies the internal cross-sectional area.
How much does water weigh?
At common conditions, water weighs about 8.34 pounds per U.S. gallon. Temperature and fluid type can change density.
Does the calculator include fittings or equipment?
No. It estimates a straight circular pipe section only. Add fittings, coils, vessels, and equipment volume separately when needed.