How to use the Water Tank Capacity Calculator
- Select tank shape.
- Enter length, or diameter for round tanks.
- Enter height.
- Tap Calculate to see the result.
- Tap Reset to clear the fields and try again.
Last updated: 1 November 2026
Water Tank Capacity Calculator
Capacity of a rectangular or round water tank.
Result
Fill in the fields and tap Calculate to see your result.
Estimates for planning only. Confirm quantities with your engineer or contractor.