Volume Calculator
Choose a 3D shape, enter its measurements, and calculate volume instantly. Measurements must use the same unit.
What Is Volume?
Volume measures the amount of three-dimensional space occupied by an object or enclosed inside a container. Unlike length, which measures one dimension, or area, which measures a flat surface, volume accounts for length, width and height—or equivalent dimensions for curved shapes. It is commonly used in construction, packaging, shipping, school mathematics, manufacturing, gardening and many household projects.
This free volume calculator helps you find the volume of five common solids: rectangular prisms, cubes, cylinders, spheres and cones. Select a shape above, enter the required dimensions, and choose a measurement unit. The calculator displays the result in cubic units, such as cm³, m³ or in³.
How to Use the Volume Calculator
- Select the 3D shape that most closely matches your object.
- Choose the unit used for your measurements.
- Enter every required dimension using positive numbers.
- Press Calculate Volume to view the answer and formula.
- Use Reset to clear the fields before calculating another object.
For a reliable answer, measure all dimensions in the same unit. For example, do not enter a length in meters and a width in centimeters unless you convert one of them first. The output is a cubic unit because volume multiplies three dimensions.
Volume Formulas for Common Shapes
Rectangular Prism
A box-shaped object, such as a storage container or rectangular tank, has volume equal to length multiplied by width multiplied by height. If a box is 30 cm long, 20 cm wide and 10 cm high, its volume is 30 × 20 × 10 = 6,000 cm³.
Cube
A cube has six equal square faces, so every edge has the same length. Multiply the side length by itself three times: V = side³. A cube with a side of 4 inches has a volume of 64 in³.
Cylinder
A cylinder has a circular base and a constant height. Its volume is V = πr²h, where r is the radius of the circular base and h is the perpendicular height. Radius is measured from the center of the circle to its edge. If you know the diameter, divide it by two before entering the radius.
Sphere
A sphere is a perfectly round three-dimensional object. Its volume formula is V = (4/3)πr³. Use the radius rather than the diameter. Examples include a ball or a spherical tank, although real objects may not be perfectly spherical.
Cone
A cone has a circular base that narrows to a point. Its volume is one-third of the volume of a cylinder with the same base radius and vertical height: V = (1/3)πr²h. The height is the straight perpendicular distance from the base to the tip, not the sloping side length.
Volume Units and Conversions
Volume is expressed in cubic units because three dimensions are multiplied together. Common metric units include cubic millimeters (mm³), cubic centimeters (cm³) and cubic meters (m³). Imperial and US customary measurements may use cubic inches (in³) or cubic feet (ft³). One cubic meter equals 1,000,000 cubic centimeters, while one cubic foot equals 1,728 cubic inches.
For liquids, capacity is often described in liters or milliliters. One liter is equal to 1,000 cubic centimeters, and one milliliter equals one cubic centimeter. These relationships are useful when estimating container capacity, but always check whether the calculator result and the unit you need are expressed in the same system.
Practical Uses of Volume Calculations
Volume calculations help estimate the capacity of a tank, the amount of material that fits inside a box, the space taken up by a package, or the quantity of concrete required for a simple solid form. Students can use the formulas to check homework, while designers and DIY users can compare dimensions before buying or building an item. For irregular objects, a single basic formula may not be accurate; the object may need to be divided into simpler shapes or measured using a suitable displacement method.
Common Mistakes to Avoid
- Mixing units: Convert all measurements to one unit before calculating.
- Using diameter as radius: The radius is half the diameter.
- Forgetting cubic units: A volume result should be expressed in units such as cm³, not cm.
- Using slant height for a cone: The standard cone formula uses vertical height.
- Assuming every object is a perfect solid: Real containers can have walls, rounded corners or uneven shapes that affect usable capacity.
Frequently Asked Questions
Is this volume calculator free?
Yes. You can use the calculator on this page without creating an account or paying a fee.
Can I calculate volume in meters or inches?
Yes. Select meters, centimeters, millimeters, inches or feet. Enter all dimensions in the selected unit to get a consistent cubic-unit answer.
What if I only know a circle’s diameter?
Divide the diameter by two to get the radius, then enter the radius for a cylinder, sphere or cone.
Can this calculate irregular objects?
The calculator supports five regular shapes. For an irregular object, you may need to split it into multiple shapes, add their volumes, or use a measurement method designed for irregular objects.
Why is the answer in cubic units?
Volume multiplies three dimensions. For example, centimeters multiplied by centimeters multiplied by centimeters gives cubic centimeters (cm³).
Note: Results are mathematical estimates based on the dimensions entered. For construction, manufacturing, storage or safety-critical capacity decisions, verify measurements and specifications independently.
Related Tools
Explore these related free tools: Area Calculator · Perimeter Calculator · Unit Converter.