Tank Volume Calculator

Last updated: 13 Sep 2026 | Author: Brij | Review By: Irshad

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Calculate cylindrical and rectangular tank capacity, filled volume, gallons, liters, and cubic feet using tank dimensions and an optional fill level.

Tank Shape:

Fill Level (optional):

Tank Length:

Tank Width:

Tank Height:

Tank Volume Calculation Results

Tank Volume:

cu ft

Filled Volume:

cu ft

Volume in Gallons:

gallons

Volume in Liters:

liters

Volume in Cubic Feet:

cu ft

A Tank Volume Calculator helps you estimate how much liquid a tank can hold based on its shape and dimensions. Select a cylindrical or rectangular tank, enter the required measurements, and optionally add a fill level to calculate the volume currently inside the tank.

The calculator returns the total tank volume, filled volume, volume in gallons, volume in liters, and volume in cubic feet.

What Does the Tank Volume Calculator Calculate?

This calculator supports:

Cylindrical tanks
Rectangular tanks
Optional fill-level calculations

It provides results for:

Total tank volume
Filled volume
Volume in cubic feet
Volume in gallons
Volume in liters

How to Use the Tank Volume Calculator

Step 1: Select the Tank Shape

Choose the tank shape that matches your tank:

Cylindrical
Rectangular

Step 2: Enter the Tank Dimensions

For a cylindrical tank, enter:

Tank diameter
Tank height

For a rectangular tank, enter:

Tank length
Tank width
Tank height

Use the same unit for every tank measurement, such as feet, metres, or inches.

Step 3: Enter the Fill Level

The fill level is optional. Enter the percentage of the tank that is currently filled.

For example:

Enter 100 for a full tank.
Enter 50 for a half-full tank.
Enter 25 for a quarter-full tank.

Step 4: View the Results

The calculator shows the total capacity of the tank and the estimated volume currently filled based on the selected fill percentage.

Cylindrical Tank Volume Formula

For a vertical cylindrical tank, use the diameter and height to calculate the total capacity.

$\text{Tank Volume} = \pi \times \left(\frac{\text{Tank Diameter}}{2}\right)^{2} \times \text{Tank Height}$

The radius is half of the tank diameter.

$\text{Tank Radius} = \frac{\text{Tank Diameter}}{2}$

Rectangular Tank Volume Formula

For a rectangular tank, multiply the length, width, and height.

$\text{Tank Volume} = \text{Tank Length} \times \text{Tank Width} \times \text{Tank Height}$

Filled Tank Volume Formula

To calculate the liquid currently inside the tank, multiply the total volume by the fill-level percentage.

$\text{Filled Volume} = \text{Tank Volume} \times \frac{\text{Fill Level}}{100}$

Tank Volume Unit Conversions

The calculator can convert the tank volume into commonly used units.

$\text{Volume in Gallons} = \text{Volume in Cubic Feet} \times 7.48052$

$\text{Volume in Liters} = \text{Volume in Cubic Feet} \times 28.3168$

The gallons conversion above uses U.S. gallons.

Example: Cylindrical Tank Volume

Suppose you have a cylindrical water tank with the following measurements:

Tank diameter: 6 feet
Tank height: 10 feet
Fill level: 75%

Step 1: Calculate the Tank Radius

$\text{Tank Radius} = \frac{6\text{ ft}}{2} = 3\text{ ft}$

Step 2: Calculate the Total Tank Volume

$\text{Tank Volume} = \pi \times 3^{2} \times 10 = 282.74\text{ ft}^{3}$

The full tank capacity is approximately 282.74 cubic feet.

Step 3: Calculate Filled Volume

$\text{Filled Volume} = 282.74\text{ ft}^{3} \times \frac{75}{100} = 212.06\text{ ft}^{3}$

At a 75% fill level, the tank contains approximately 212.06 cubic feet of liquid.

Step 4: Convert the Total Capacity

$\text{Volume in Gallons} = 282.74 \times 7.48052 = 2114.9\text{ gallons}$

$\text{Volume in Liters} = 282.74 \times 28.3168 = 8006.4\text{ liters}$

The tank has an estimated full capacity of about 2,115 gallons or 8,006 liters.

Important Notes

Measure the inside dimensions of the tank for the most accurate capacity estimate.
Use the same measurement unit for all dimensions.
Enter the tank diameter, not the radius, for cylindrical tanks.
The fill-level result is an estimate based on the percentage entered.
Confirm final capacity with the tank manufacturer when precision is important.

Frequently Asked Questions

What is the difference between tank volume and filled volume?

Tank volume is the total amount of liquid the tank can hold. Filled volume is the amount currently inside the tank based on the fill level entered.

How do I calculate the volume of a cylindrical tank?

Divide the diameter by 2 to find the radius, then multiply pi by the radius squared and the tank height.

$\text{Tank Volume} = \pi \times \text{Radius}^{2} \times \text{Height}$

How do I calculate the volume of a rectangular tank?

Multiply the tank length, width, and height.

$\text{Tank Volume} = \text{Length} \times \text{Width} \times \text{Height}$

Can I enter a partially filled tank?

Yes. Enter the fill level as a percentage to estimate the amount of liquid currently in the tank.

Does this calculator support oval tanks?

This calculator is designed for cylindrical and rectangular tanks. Oval tank calculations require different dimensions and a separate volume formula.

Does the calculator use U.S. gallons or Imperial gallons?

The conversion uses U.S. gallons. One cubic foot equals approximately 7.48052 U.S. gallons.

Can I use this calculator for water, fuel, or other liquids?

Yes. The calculator estimates physical tank capacity, which is the same regardless of the liquid. Follow all relevant safety, storage, and handling requirements for the liquid in your tank.

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