Volume Calculator

Using the calculator is straightforward. Start by selecting the shape you're working with. Each shape has its own section with labeled input fields for the dimensions you need, like length, width, height, or radius.

Type your measurements into the fields. Make sure all your numbers are in the same unit before you start. If your length is in inches, your width and height should be in inches too. The result will come out in cubic units matching whatever you entered.

Hit calculate, and you'll see the volume displayed instantly. If you need to convert that result to a different unit, like from cubic inches to gallons or liters, scroll down to the unit conversion section at the bottom of the page.

A cube is the simplest case. All six faces are identical squares, which means all three dimensions are the same length. You only need one number to calculate the volume.

The formula is just the side length cubed: V = s³. So if your cube has sides of 4 inches, the volume is 4 × 4 × 4 = 64 cubic inches. Clean and simple.

Common uses include calculating the volume of dice, storage boxes that happen to be perfectly square, and ice cubes. It also shows up a lot in math class when students are first learning about volume.

A rectangular prism is basically a box shape. Think of a shoebox, a shipping container, a room in your house. It has three distinct dimensions: length, width, and height.

The formula is V = l × w × h. Multiply those three values together and you've got your volume. A box that's 10 inches long, 6 inches wide, and 4 inches tall has a volume of 240 cubic inches.

This is one of the most practical shapes for real-world use. Calculating how much soil fits in a raised garden bed, how much space is inside a storage unit, or how many cubic feet a room contains all come back to this same formula. Straightforward stuff, but genuinely useful.

Cylinders show up everywhere: water tanks, soup cans, pipes, wine barrels. Calculating the volume of a cylinder requires two measurements: the radius of the circular base and the height (or length) of the cylinder.

If you know the diameter instead of the radius, just divide by 2. The radius is always half the diameter. Once you have those two numbers, you're ready to calculate.

Spheres are perfectly round in every direction. Balls, globes, bubbles, tanks that hold pressurized gas. To calculate the volume of a sphere, you only need the radius.

Like with a cylinder, if you're starting with the diameter, divide it by 2 to get the radius first. Once you have that single measurement, you can find the volume using the formula below.

A cone has a circular base that tapers to a point at the top. Ice cream cones, traffic cones, and funnels are the classic examples. You need two measurements: the radius of the circular base and the height from the base to the tip.

One thing worth remembering: the height here is the vertical height, not the slant height along the side of the cone. Those are different, and using the slant height by mistake will give you the wrong answer.

Pyramids and prisms cover a wide range of shapes, and their volumes are calculated a bit differently from each other.

For a rectangular pyramid (a box shape that comes to a point), the formula is V = (1/3) × l × w × h. Just like the cone is one-third of a cylinder, a pyramid holds one-third the volume of a rectangular prism with the same base and height.

For a prism (any solid with two parallel, identical bases connected by flat sides), the formula is V = base area × height. The base can be a triangle, hexagon, or any other polygon. Calculate the area of that base shape, then multiply by the height of the prism. A triangular prism, for instance, uses the area of the triangle as its base area: V = (1/2 × b × h_triangle) × H, where H is the length of the prism.

Here's a quick reference for the formulas covered on this page. All variables use standard notation: r = radius, h = height, l = length, w = width, s = side length.

Bookmark this table or print it out if you find yourself doing volume calculations regularly. Having the formulas in one place saves a lot of back-and-forth searching.

Seeing the formulas in action makes them a lot easier to remember. Here are a few worked examples across different shapes.

• Cube: Side length = 6 ft. Volume = 6³ = 216 cubic feet.
• Rectangular Prism: Length = 8 m, width = 3 m, height = 2 m. Volume = 8 × 3 × 2 = 48 cubic meters.
• Cylinder: Radius = 2 in, height = 7 in. Volume = π × 4 × 7 ≈ 87.96 cubic inches.
• Sphere: Radius = 6 cm. Volume = (4/3) × π × 216 ≈ 904.78 cubic centimeters.
• Cone: Radius = 5 ft, height = 12 ft. Volume = (1/3) × π × 25 × 12 ≈ 314.16 cubic feet.

These examples use clean numbers to keep the math readable, but the same process applies no matter what values you're working with. Identify the shape, pull the right formula, and substitute your measurements.

Once you have a volume in cubic units, you might need to convert it to something more practical, like gallons, liters, or cubic yards. Here are the most useful conversions to know.

A couple of quick tips: 1 liter equals exactly 1,000 cubic centimeters, and 1 US gallon is about 231 cubic inches. Those two are worth memorizing if you do a lot of liquid volume work. For everything else, the table above has you covered.