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- Volume is the space inside a 3D shape, written in cubic units such as cm³ or ft³.
- Pick a shape and a unit, enter the measurements, and the calculator returns the volume and the surface area.
- Every result is also shown in liters, US gallons, cubic meters, cubic feet, cubic inches and milliliters.
- Use the same unit for every measurement of the shape.
How to use the volume calculator
Choose the shape
Pick a box, cube, cylinder, sphere, hemisphere, cone or pyramid. The fields below change to match the shape.
Pick your unit
Choose millimeters, centimeters, meters, inches, feet or yards. All measurements use the same unit.
Enter the measurements
Fill in the length, width, height, side or radius that the shape needs. The radius is half of the diameter.
Read the result
You get the volume and surface area, conversions to liters and gallons, and the formula with your own numbers filled in.
Volume formulas
Every shape has its own formula, but each one measures how many unit cubes fit inside. Here are the formulas the calculator uses.
Shapes with flat sides
Box: V = l × w × h
Cube: V = a³
Pyramid with a rectangular base: V = ⅓ × l × w × h
l is the length, w the width, h the height and a the side. For a pyramid, h is the straight height from the base to the tip.
Round shapes
Cylinder: V = π × r² × h
Cone: V = ⅓ × π × r² × h
Sphere: V = 4/3 × π × r³
Hemisphere: V = 2/3 × π × r³
r is the radius, which is half of the diameter, and π is about 3.14159.
A useful pattern: a cone holds exactly one third of the cylinder with the same radius and height, and a pyramid holds one third of the box with the same base and height.
Worked examples
A water tank shaped like a cylinder
A cylinder has a radius of 0.5 m and a height of 1.2 m. Choose Cylinder, set the unit to meters and enter both numbers.
The tank holds roughly 942 liters when it is full.
A shipping box
A box measures 60 cm long, 40 cm wide and 30 cm high.
The 72 liters is handy when you compare box sizes or check how much a package can hold.
Volume unit conversions
Quick reference
Cubic units grow fast, so it helps to know the common conversions.
The calculator shows liters, US gallons, cubic meters, cubic feet, cubic inches and milliliters for every result, so you rarely need to convert by hand.
Where a volume calculator helps
Moving, shipping and storage
Compare box and container sizes, or check how much a crate or a shelving unit really holds.
Concrete, soil and gravel
Find the volume of a slab or a garden bed in cubic feet, then divide by 27 to get the cubic yards you need to order.
Tanks, pools and aquariums
Turn the dimensions into liters or US gallons to size a pump, a filter or water treatment.
Homework and design
Check your working on geometry problems and see each formula with your numbers filled in.
To find how much a container holds, measure its inside. Outside measurements include the thickness of the walls and overstate the capacity.
Volume calculator FAQ
How do I find the volume of a cylinder?
Multiply π by the radius squared and then by the height: V = π × r² × h. A cylinder with a radius of 3 and a height of 3 has a volume of about 84.82 cubic units.
What is the difference between volume and surface area?
Volume is the space inside a shape and is measured in cubic units, such as cm³. Surface area is the total area of the outside and is measured in square units, such as cm². Think of volume as how much water fills a box and surface area as how much paper wraps it.
What if I know the diameter, not the radius?
Divide the diameter by 2 and enter the result as the radius.
How do I convert cubic feet to cubic yards?
Divide by 27. One yard is 3 feet, and 3 × 3 × 3 = 27 cubic feet in a cubic yard.
Can I mix units, such as feet and inches?
Not in one calculation. Convert every measurement to the same unit first, for example 2 ft 6 in becomes 30 in, then enter them all in that unit.
Does it work for slanted cones and pyramids?
The volume formulas stay the same for a slanted cone or pyramid as long as you enter the perpendicular height, which is the straight distance from the base up to the tip. The surface area shown assumes a straight (right) cone or pyramid.