Tank Volume Calculator
Free tank volume calculator. Find the capacity in gallons and litres of a cylindrical, rectangular or capsule tank from its dimensions. For fuel, water and storage tanks.
About the Tank Volume Calculator
Calculate full tank capacity for a rectangular, cylindrical or capsule shape from its internal dimensions. Imperial mode displays US gallons and cubic feet; metric mode displays liters and cubic meters. A capsule is modeled as a cylinder with hemispherical ends. The result is total capacity, not volume at a partial liquid level. Use this tank volume calculator for simple capacity planning and check actual internal dimensions before relying on the estimate.
Features
- Rectangular, cylindrical and capsule tanks
- Internal-dimension full-capacity calculation
- US gallons and cubic feet in imperial mode
- Liters and cubic meters in metric mode
- Copy the result
How to use this tool
The Tank Volume Calculator works right in your browser — no signup, no installation. Follow these steps:
- Choose the tank shape.
- Select imperial or metric units.
- Enter the internal dimensions; capsule length includes both rounded ends.
- Read full capacity and volume, then copy the result.
Frequently asked questions
Which units are displayed?
Imperial mode shows US gallons and cubic feet. Metric mode shows liters and cubic meters. Use the units selector to switch.
Can I calculate a partially filled horizontal tank?
No. This calculator returns full capacity. A partial fill requires a different formula and the liquid level.
What is a capsule tank?
The model combines a cylinder with two hemispherical ends. Enter the full end-to-end length, including the rounded ends.
Using the results
The Tank Volume Calculator estimates quantities from your measurements and the stated assumptions. Check dimensions, product coverage and project requirements before buying materials.