Tank Volume Calculator

Select the style of tank and its dimensions to calculate the capacity in gallons and liters. Optionally, enter the filled depth to calculate the volume of liquid in a tank.

Calculate Horizontal Cylinder Tank Volume

horizontal cylinder tank diagram showing length, diameter, and fill depth dimensions

Calculate Vertical Cylinder Tank Volume

vertical cylinder tank diagram showing height, diameter, and fill depth dimensions

Calculate Horizontal Oval Tank Volume

horizontal oval tank diagram showing length, width, height, and fill depth dimensions

Calculate Vertical Oval Tank Volume

vertical oval tank diagram showing length, width, height, and fill depth dimensions

Calculate Horizontal Capsule Tank Volume

horizontal capsule tank diagram showing side length, diameter, and fill depth dimensions

Calculate Vertical Capsule Tank Volume

vertical capsule tank diagram showing side length, diameter, and fill depth dimensions

Calculate Rectangular Tank Volume

rectangular tank diagram showing length, width, height, and fill depth dimensions

Calculate Sphere Tank Volume

sphere tank diagram showing diameter and fill depth dimensions

Tank Volume Estimate:

gallons

liters

Filled Volume

gallons

liters

Learn how we calculated this below

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How to Calculate Tank Volume

You can find the volume or capacity of a tank in a few easy steps. Of course, the calculator above is the easiest way to calculate tank volume, but follow along to learn how to calculate it yourself.

Step One: Measure the Tank

The first step is to measure the key dimensions of the tank. For round tanks, find the diameter and length or height. For rectangular or cubes, find the length, width, and height.

Step Two: Find the Tank Volume Formula

In order to calculate a tank’s capacity, you’ll need a formula for volume. The volume formula varies for each style of tank. See the formulas below and select the one for your style.

Cylinder Tank Formula

tank volume = π × r² × l

r = radius (diameter ÷ 2)
l = length (or height for a vertical tank)

Diagram of a cylinder tank showing the diameter and length dimensions

Oval Tank Formula

area = ((h – w) × w) + (π × r²)
tank volume = area × l

r = radius (tank width ÷ 2)
w = width
l = length
h = height

Diagram of an oval tank showing the length, width, and height dimensions

Capsule Tank Formula

cylinder volume = π × r² × l
sphere volume = 4/3 π × r³
tank volume = cylinder volume + sphere volume

r = radius (diameter ÷ 2)
l = length (or height for a vertical tank)

Diagram of a capsule tank showing the diameter and length dimensions

Rectangular Tank Formula

tank volume = l × w × h

l = length
w = width
h = height

Diagram of a rectangular tank showing the length, width, and height dimensions

Not finding a formula for the shape of your tank? Find even more volume formulas.

Step Three: Solve the Volume Formula

When you have the tank dimensions and the appropriate formula to solve for volume, simply enter the dimensions into the formula and solve.

For example, let’s find the volume of a cylinder tank that is 36″ in diameter and 72″ long.

radius = 36″ ÷ 2
radius = 18″

tank volume = π × 18² × 72
tank volume = 73,287 cu in

Thus, the capacity of this tank is 73,287 cubic inches.

Step Four: Convert Volume Units

The resulting tank volume will be in the cubic form of the initial measurements. For instance, if the initial tank measurements were in inches, then the volume measurement would be in cubic inches.

You’ll often need the volume in another form, such as gallons or liters.

Thus, the final step is to convert from one volume measurement to the desired unit of the result. Try our volume converter to convert the results to gallons, liters, or any other unit.

Curious how much a tank full of water weighs? Calculate it using our water weight calculator.