Summary: calculate volume for 8 shapes, free and private
A volume calculator works out how much space a three-dimensional object takes up. To calculate a volume for free and privately, select a shape in the tool above, choose the unit you measured in, and enter each dimension. The result appears in that unit cubed, with the formula and the same volume in liters, milliliters, cubic meters, US and UK gallons, cubic feet, cubic inches and cubic yards. It runs in your browser; nothing is uploaded, and the Network tab in DevTools will show that.
Volume is measured in cubic units: a box 2 m × 3 m × 4 m is 2 × 3 × 4 = 24 m³, and because 1 m³ is 1,000 liters, that is 24,000 liters. Every dimension has to be in the same unit, and the calculator needs a value greater than zero in each field. For flat shapes, the Area Calculator is the one to use.
Table of Use: formulas and worked examples
| Shape | Formula | You enter | You get |
|---|---|---|---|
| Cube | V = side³ | Side 12 in | 1,728 in³ (1 ft³, 28.31684659 L) |
| Rectangular prism | V = l × w × h | 2 × 3 × 4 m | 24 m³ (24,000 L) |
| Rectangular prism (fish tank) | V = l × w × h | 60 × 30 × 30 cm | 54,000 cm³ (54 L, 14.27 US gal) |
| Rectangular prism (concrete slab) | V = l × w × h | 4 × 3 × 0.1 m | 1.2 m³ (1,200 L) |
| Sphere | V = 4/3 × π × r³ | Radius 0.5 m | 0.5235987756 m³ (523.6 L) |
| Cylinder | V = π × r² × h | Radius 2 m, height 5 m | 62.83185307 m³ (62,831.85 L) |
| Cone | V = 1/3 × π × r² × h | Radius 3 cm, height 10 cm | 94.24777961 cm³ (94.25 mL) |
| Square pyramid | V = 1/3 × base² × h | Base 10 ft, height 6 ft | 200 ft³ (5,663.37 L) |
| Torus | V = 2 × π² × R × r² | R 3 in, r 1 in | 59.21762641 in³ |
| Ellipsoid | V = 4/3 × π × a × b × c | a 3 m, b 2 m, c 1 m | 25.13274123 m³ |
Features
- Eight shapes. Cube, rectangular prism, sphere, cylinder, cone, square pyramid, torus and ellipsoid, each with its formula on screen.
- Six length units. Meters, centimeters, millimeters, feet, inches and yards. To change a measurement first, use the Length Converter.
- Conversions built in. Under In other units: liters, mL (cm³), m³, US gallons, UK gallons, ft³, in³ and yd³, using exact factors such as 1 US gallon = 3.785411784 L. For other volume units, try the Unit Converter.
- Dimensions carry over. A radius or height you typed stays when you switch to another shape that uses it, so comparing a sphere, cylinder and cone is quick.
- Flexible input. Decimals with a point or a comma, and scientific notation such as 1e-3.
- Clear messages for zero, negative or non-numeric entries, and when a torus tube radius is larger than the major radius.
- Copy button that copies the result with its unit, for example 24 m³.
It handles solid shapes with exact dimensions. It does not work out partly filled containers, wall thickness or irregular objects.
How to Use the Volume Calculator
- Select shape. Click the button that matches your object, such as Cylinder for a round tank.
- Set the Unit of the dimensions to the unit you measured in.
- Fill in the fields (for a box: Length, Width and Height). All of them must be above zero.
- Read the Result in your unit cubed, then check the Formula and In other units panels.
- Copy it with the copy icon next to the Result heading.
Measuring a container? Use the inside dimensions for its capacity. For a bulk-material order such as concrete or soil, add a waste allowance with the Percentage Calculator, and turn the volume into a weight by multiplying by the material's density, then converting with the Weight Converter.
Who Can Use It
- Students checking geometry homework against the formula and a worked result. The Scientific Calculator handles the rest of the arithmetic.
- DIY builders and gardeners estimating concrete, soil or mulch in m³ or yd³.
- Aquarium, pond and water-tank owners turning dimensions into liters or gallons.
- Shippers and packers comparing the capacity of boxes and containers.
- Anyone with fractional measurements can add them up first with the Fraction Calculator. More tools sit in the calculators hub.
Frequently Asked Questions
How do I calculate the volume of a box?
Multiply length × width × height, all in the same unit. A box 2 m long, 3 m wide and 4 m high holds 2 × 3 × 4 = 24 m³, which is 24,000 liters. Choose Rectangular Prism in the calculator and enter the three dimensions in one unit; the result is in that unit cubed.
How do I find the volume of a cylinder, such as a round tank?
Use V = π × r² × h, where r is the radius (half the diameter) and h is the height. A tank with a radius of 2 m and a height of 5 m holds π × 4 × 5 ≈ 62.83 m³, or about 62,832 liters. Measure the inside dimensions if you need capacity rather than outer size.
How do I convert cubic meters to liters or gallons?
1 cubic meter is exactly 1,000 liters, and 1 cubic centimeter is 1 milliliter. 1 m³ is about 264.17 US gallons or 219.97 UK (imperial) gallons, and 1 cubic foot is about 28.32 liters or 7.48 US gallons. The calculator lists these under In other units, below the result.
How many liters does a fish tank hold?
Multiply the inside length, width and height in centimeters, then divide by 1,000. A tank of 60 × 30 × 30 cm is 54,000 cm³, which is 54 liters, or about 14.27 US gallons. Enter the three sizes with the unit set to Centimeters (cm). A filled tank holds slightly less once gravel and decorations are in.
Why is a cone one third of a cylinder?
A cone with the same base and height as a cylinder holds exactly one third of the cylinder's volume, so V = 1/3 × π × r² × h. The same one-third rule links a pyramid to a prism with the same base and height: V = 1/3 × base area × height.
What are the major and minor radius of a torus?
The major radius R is the distance from the centre of the hole to the centre of the tube; the minor radius r is the radius of the tube itself. The volume is 2 × π² × R × r². For a ring-shaped torus r cannot be larger than R, and the calculator shows a message if it is.
Is it safe to enter my measurements into an online volume calculator?
With this one, yes. The volume calculator runs in your browser, so the measurements you type are not uploaded or stored, and there is no sign-up. You can check the Network tab in your browser's DevTools: calculating a volume sends no request.