Cube Shape Calculator
Free online cube shape calculator. Calculate the volume, surface area, face diagonal, and solid diagonal of a cube given any one known dimension.
What is a Cube?
A cube is a three-dimensional solid object bounded by six square faces, facets, or sides, with three meeting at each vertex. It is one of the five Platonic solids and is also known as a regular hexahedron. The cube is a special case of a rectangular prism where the length, width, and height are all equal.
The cube shape calculator helps you compute all essential properties of a cube: the side length (a), face diagonal (f), solid diagonal (d), surface area (S), and volume (V). You can enter any one known value and the tool will automatically calculate the remaining four.
How to Use the Cube Shape Calculator
Using this cube geometry calculator is simple. Follow these steps:
- Select Known Value: Choose which cube property you know from the dropdown menu (side length, face diagonal, solid diagonal, surface area, or volume).
- Choose Unit: Select your preferred unit of measurement (mm, cm, m, km, in, ft, yd, or none).
- Enter Value: Input the known value into the calculator.
- Adjust Precision: Set the number of significant figures for the results (auto, 3-9).
The results update in real-time as you type. The currently selected input mode is highlighted in the results section for easy reference.
Cube Formulas
The following formulas are used to calculate the properties of a cube where a is the side length:
V = a³
Volume of a cube
S = 6a²
Surface area (area of each face a x a times 6 faces)
f = a√2
Face diagonal (using the Pythagorean theorem f² = a² + a²)
d = a√3
Solid diagonal (d² = a² + f² = a² + 2a² = 3a²)
How to Derive Other Values
If you know the face diagonal (f), the side length can be found as a = f / √2. From the solid diagonal (d), a = d / √3. From the surface area (S), a = √(S / 6). From the volume (V), a = ³√V. Once the side length is determined, all other properties are computed using the formulas above.
Example Calculation
Example: Find the volume, surface area, face diagonal, and solid diagonal of a cube with side length a = 4 cm.
- Volume: V = 4³ = 64 cm³
- Surface Area: S = 6 x 4² = 96 cm²
- Face Diagonal: f = 4 x √2 = 5.657 cm
- Solid Diagonal: d = 4 x √3 = 6.928 cm
Simply select "Side Length (a)" from the dropdown, enter 4, and choose cm as the unit. All four results will be displayed instantly.
For more geometry and math tools, try the Cube Calculator, Volume Calculator, Surface Area Calculator, and Rectangular Prism Calculator.
Frequently Asked Questions
What is the difference between a face diagonal and a solid diagonal in a cube?
A face diagonal is a line segment joining two opposite vertices on the same face of the cube. A solid diagonal (also called a space diagonal) is a line segment joining two opposite vertices that are not on the same face, passing through the interior of the cube. The face diagonal is shorter (a√2) than the solid diagonal (a√3).
Can I calculate cube properties if I only know the surface area?
Yes. If you know the surface area, you can find the side length by taking the square root of the surface area divided by 6 (a = √(S/6)). Then use the side length to calculate the volume, face diagonal, and solid diagonal using the standard formulas.
How many faces, edges, and vertices does a cube have?
A cube has 6 faces (all squares), 12 edges (all equal in length), and 8 vertices. It is one of the five Platonic solids and satisfies Euler's formula: V - E + F = 2 (8 - 12 + 6 = 2).
What units does the cube shape calculator support?
The calculator supports millimeters (mm), centimeters (cm), meters (m), kilometers (km), inches (in), feet (ft), yards (yd), and a "None" option for unitless calculations. The surface area results use squared units and volume results use cubic units of the selected measurement.
Is a cube the same as a rectangular prism?
A cube is a special case of a rectangular prism where the length, width, and height are all equal. While a rectangular prism can have different dimensions for each side, a cube has identical dimensions on all sides, making it a regular hexahedron.
What is the volume of a cube with a side length of 10 cm?
The volume of a cube with side length 10 cm is V = 10³ = 1,000 cubic centimeters (cm³). In liters, this would be 1 liter since 1,000 cm³ = 1 L. The surface area would be S = 6 x 10² = 600 cm².