Volume Calculator
This volume calculator handles every common 3D shape in one place. Pick a cube, box, cylinder, sphere, cone, pyramid, or triangular prism, type in the dimensions, and you'll get the volume right away, with the formula shown and the answer in cubic units, liters, gallons, and cubic feet. It's the fast way to find the volume of a shape or solid without looking up a different formula each time.
- 7 shapes in one tool
- Formula shown
- Gallons, liters, cubic feet
- Live diagram
- Links to each full tool
Last updated June 16, 2026 Covers 7 shapes Reviewed by the Calcowa math team
Enter positive numbers to see the volume.
Show all volume units
V = l × w × h
What is volume?
Volume is the amount of space a 3D shape takes up, measured in cubic units. If you imagine filling a solid with tiny cubes, the volume is how many cubes fit inside. That's why a box 2 inches on every side holds 8 cubic inches, not 6. Volume always uses cubes because a shape fills three directions at once: length, width, and height.
Area covers a flat surface and uses square units, while volume fills a solid and uses cubic units. Liquids get measured in liters or gallons, but those are the same idea, just friendlier names for the space inside a tank or bottle.
Volume formula for each shape
There isn't a single volume formula that fits every shape, so here's the volume formula for the seven shapes this tool covers. Tap any row to open that shape's full calculator with extra options.
| Shape | Formula | In words |
|---|---|---|
| Cube | V = s³ | One side cubed |
| Rectangular box | V = l × w × h | Length times width times height |
| Cylinder | V = π r² h | Circle base times height |
| Sphere | V = 4/3 π r³ | Four-thirds pi times radius cubed |
| Cone | V = 1/3 π r² h | A third of the matching cylinder |
| Square pyramid | V = 1/3 a² h | A third of base area times height |
| Triangular prism | V = ½ b h L | Triangle area times prism length |
Notice the pattern: a cone is exactly a third of the cylinder it fits inside, and a pyramid is a third of its box. That 1/3 link is worth remembering.
How do you calculate volume?
To calculate volume, match your object to a shape, measure it, and apply that shape's formula. Here's the routine that works every time:
- 1
Pick the matching shapeA can is a cylinder, a ball is a sphere, a moving carton is a box.
- 2
Measure in one unitMeasure every dimension in the same unit so the math lines up.
- 3
Apply the formulaMultiply the dimensions using the shape's formula above.
- 4
Convert if you need toTurn the cubic answer into gallons, liters, or cubic feet.
Volume in gallons, liters, and cubic feet
Once you've got the volume in cubic units, converting to gallons or liters is just one more step, and this calculator shows them for you. One US gallon is 231 cubic inches, one liter is 1,000 cubic centimeters, and one cubic foot is 1,728 cubic inches. So a tank that measures 600 cubic inches holds about 2.6 gallons. If you're filling a pool, fish tank, or fuel drum, the gallons and liters figures are what you'll actually use.
Volume of a box or container
A box is the simplest solid to measure, which is why it's the one most people start with. The volume of a box or container is length times width times height, so a carton 12 by 10 by 8 inches holds 960 cubic inches. Pick Rectangular box above to work yours out, and if you want the surface area and the longest diagonal as well, the rectangular prism volume calculator covers those too.
How to find the volume of an irregular shape
Not everything is a neat cube or cylinder. For an irregular shape, you've got two reliable options. You can split it into shapes you recognize, find each volume, and add them up. Or you can use water displacement: lower the object into a measuring jug of water, and the amount the water rises is the object's volume. There's no tidy formula for a truly irregular solid, so one of those two methods is how it's done.
Volume units and accuracy
Calcowa shows the volume in cubic millimeters through cubic yards, plus liters, milliliters, and US gallons, all at once. The math uses the full value of pi for round shapes, so the cubic volume is accurate for shipping, tanks, gardening, and school work alike.
| Unit | Best for | Good to know |
|---|---|---|
| Cubic inches (in³) | Small parts, shipping | Default when you enter inches |
| Cubic feet (ft³) | Rooms, soil, concrete | 1 ft³ = 1,728 in³ |
| Cubic meters (m³) | Large tanks, construction | 1 m³ = 1,000 liters |
| Liters (L) | Liquids and containers | 1 L = 1,000 cm³ |
| US gallons (gal) | Tanks, pools, fuel | 1 US gal = 231 in³ |
Frequently asked questions
Is volume always measured in cubic units?
Yes. Volume fills three dimensions, so it's measured in cubic units like cubic inches or cubic meters. Liters and gallons are cubic measures too, just under everyday names, so they count as volume as well.
Pick the shape, then multiply its dimensions with the matching formula. A box is length times width times height. A cylinder is pi times the radius squared times the height. The calculator above does it for seven common shapes once you type the numbers in.
There isn't one formula for every shape. A cube is s³, a rectangular box is l × w × h, a cylinder is π r² h, a sphere is 4/3 π r³, and a cone or pyramid is a third of the matching prism. The table on this page lists all of them side by side.
Multiply pi by the radius squared by the height: V = π r² h. For a radius of 3 inches and a height of 10, that's about 283 cubic inches. The full cylinder volume calculator adds hollow pipes and fill levels.
Multiply length by width by height. A box 4 by 3 by 2 inches holds 24 cubic inches. Pick Rectangular box above, or open the rectangular prism volume calculator for the surface area and diagonal too.
Work out the volume in cubic units first, then convert. One US gallon is 231 cubic inches, and one liter is 1,000 cubic centimeters. This calculator shows gallons, liters, and cubic feet beside the main result, so you don't have to convert by hand.
Break it into shapes you can measure and add the parts, or use water displacement: drop the object in a measuring jug, and the rise in water level is its volume. There's no single formula for a truly irregular solid, so one of those two methods is the way to go.
Volume is always measured in cubic units, like cubic inches, cubic feet, or cubic meters, because it fills three dimensions. Liquid volumes often use liters or gallons instead, which are just friendlier names for the same thing.
Volume calculators by shape
Need more options for one shape? Open its dedicated calculator for hollow parts, fill levels, and surface area.
Solid or hollow, with fill level.
Sphere volumeBall or hemisphere from the radius.
Cone volumeCone or truncated frustum.
Rectangular prism volumeBox, with surface area too.
Triangular prism volumeFrom the triangle base and length.
CubeVolume, surface area, diagonals.
Need a different shape?
Switch shapes in the tool above, or browse the full geometry hub.