Volume Calculator

Volume of any common solid

Volume is how much space a three-dimensional object takes up, measured in cubic units. Choose a solid, enter its dimensions, and this calculator returns the volume and the formula behind it. Like area, it's unit-agnostic — enter centimeters and you get cm³, enter inches and you get in³.

The formulas

• Box (rectangular prism): length × width × height
• Cube: side³
• Cylinder: π × radius² × height
• Sphere: 4⁄3 × π × radius³
• Cone: ⅓ × π × radius² × height — exactly one-third of the cylinder that would enclose it

A useful relationship

A cone holds exactly one-third the volume of a cylinder with the same base and height, and a sphere holds two-thirds of the cylinder that just contains it. These ratios are handy sanity checks: if your cone comes out bigger than the matching cylinder, something's wrong.

Volume and capacity

Volume connects directly to liquid capacity. One cubic centimeter equals one milliliter, and one cubic meter is 1,000 liters. So a tank's volume in cm³ is also its capacity in mL — convert to liters or gallons from there if you need a capacity figure.

FAQ

I have the diameter, not the radius.

Halve it. The radius is always half the diameter, for cylinders, spheres, and cones alike.

How do I find the volume of an irregular object?

Break it into simple solids, find each volume, and add them — or, for a physical object, use water displacement: the rise in water level when you submerge it equals its volume.

What units does it use?

It is unit-agnostic: enter all dimensions in the same unit and the result is in those cubic units — centimeters give cm³, inches give in³. Just keep every measurement in one unit to avoid errors.

How do I convert the volume to liters or gallons?

Volume equals capacity: one cubic centimeter is one milliliter, and one cubic meter is 1,000 liters. So compute the volume in cm³ or m³, then convert to milliliters, liters, or gallons as needed.

Which solids can it calculate?

It handles boxes (rectangular prisms), cubes, cylinders, spheres, and cones, showing the formula it uses for each so you can check the math or learn it.

Is it free, and does it run in my browser?

Yes to both. The calculator is free with no sign-up, the math runs locally in your browser so nothing is uploaded, and it works on phones and tablets.