Volume Calculator
This volume calculator finds the volume of a box, cube, cylinder, sphere, hemisphere, cone, pyramid, or triangular prism. Pick the shape and units, enter the sizes, and the volume calculator returns the volume in your units plus liters, cubic meters, cubic feet, and US gallons, along with the surface area.
Results
The Volume Calculator is part of our Geometry collection. Browse more geometry to size, convert, and check your work alongside this tool.
What the volume calculator does
Volume is the space a solid takes up. Every common shape has its own volume formula, and the volume calculator applies the right one as soon as you pick the shape: length times width times height for a box, π r² h for a cylinder, and 4/3 π r³ for a sphere. It then converts the result to the units you need for buying, filling, or shipping, from liters and gallons to cubic feet and cubic meters.
Volume formulas for each shape
The volume calculator uses these volume formulas, with r as half the diameter:
A cone holds one third of the cylinder with the same base and height, and a pyramid one third of the matching box.
Volume calculator example
A box 30 × 20 × 10 cm:
That is 0.2119 cubic feet or 1.585 US gallons, with 2,200 cm² of surface. A cylinder 12 in across and 36 in tall holds 4,071.5 in³, which is 66.72 liters or 17.626 gallons. A sphere 20 cm across holds 4.189 liters.
How to use the volume calculator
Choose the shape and the units, then fill in the dimensions the shape needs. Dimension A is the length, side, or diameter; B is the width; C is the height or length. A cylinder needs the diameter in A and the height in C; a sphere needs only the diameter in A. Fields a shape does not use are ignored. Press Calculate to read the volume and the surface area.
Reading the volume of a shape
The first figure is in the cube of your input unit, cm³ for centimeters or ft³ for feet. The converted figures let you match whatever the job uses: liters for liquids, gallons for US containers, cubic feet for soil and storage, and cubic meters for concrete and freight. The surface area is the outside skin, useful for paint, wrap, or insulation. Check that every dimension uses the same unit before you trust the result.
When to use a cubic feet calculator
- Finding how many liters or gallons a container holds
- Working out cubic feet of storage or moving space
- Checking the volume of a cylinder tank or drum
- Solving geometry homework on spheres, cones, and pyramids
- Converting box sizes to volume for shipping
Common volume calculator mistakes
- Using radius instead of diameter. The calculator asks for the diameter; it halves it for you.
- Mixing units. Measure every dimension in the same unit.
- Outside versus inside sizes. Use inside sizes for capacity.
- Wrong slot for height. Height goes in dimension C for cylinders, cones, and pyramids.
Tips for accurate volume results
- Measure twice and use the average for uneven objects.
- Split complex objects into simple shapes and add them.
- Add 5 to 10% when ordering bulk material by volume.
How to calculate volume for real objects
Most real objects are a mix of simple shapes. A silo is a cylinder with a cone on top, a capsule tank is a cylinder with a hemisphere at each end, and a planter may be a box with a smaller box missing. Split the object into those parts, run each through the volume calculator, and add or subtract. For containers, measure the inside to get the capacity and the outside to get the space it takes up. Units cause most errors: a box measured in inches and entered as centimeters is off by a factor of more than 16. Pick the unit you measured in and let the converted results handle the rest. For liquid in pipework, the pipe volume calculator works per meter of run, which is quicker for long lines.
Volume of a cone, sphere, and pyramid explained
The one third rule links three shapes: a cone has one third of the volume of the cylinder that would enclose it, and a pyramid one third of its enclosing box. A sphere fills two thirds of the cylinder that just contains it, a result Archimedes was proud enough of to want on his tomb. These ratios make quick checks easy. If a 10 cm wide, 15 cm tall cone gives 392.7 cm³, the matching cylinder must hold three times that, 1,178 cm³. For shipping, carriers price by volume too, so convert carton sizes with the CBM calculator before you book freight.
Volume formulas chart
Volume and surface area formulas for each shape in the volume calculator:
| Shape | Volume formula | Surface area formula |
|---|---|---|
| Cube | a³ | 6a² |
| Rectangular box | L × W × H | 2(LW + LH + WH) |
| Cylinder | π r² h | 2π r (r + h) |
| Sphere | 4/3 π r³ | 4π r² |
| Hemisphere | 2/3 π r³ | 3π r² |
| Cone | π r² h ÷ 3 | π r (r + √(r² + h²)) |
| Rectangular pyramid | L × W × h ÷ 3 | base + 4 triangular faces |
| Triangular prism | ½ b h × L | depends on the triangle sides |
Volume Calculator FAQ
How do you calculate volume?
Use the formula for the shape. For a box multiply length, width, and height; for a cylinder use π r² h; for a sphere 4/3 π r³. A 30 × 20 × 10 cm box holds 6,000 cm³, or 6 liters.
How do I convert volume to liters?
One liter is 1,000 cm³ and 1,000 liters is one cubic meter. One cubic foot is 28.32 liters, and one US gallon is 3.785 liters. The volume calculator shows these conversions for you.
What is the volume of a cylinder?
Multiply π by the radius squared and by the height. A cylinder 12 in across and 36 in tall holds 4,071.5 cubic inches, or 17.6 US gallons.
How do I find cubic feet?
Measure in feet and multiply length × width × height. A 10 × 8 ft area filled 0.5 ft deep is 40 cubic feet. With inches, divide cubic inches by 1,728.