🧊 Cube Calc: find V, a, d

Calculate volume, edge length, and space diagonal of a cube

How to Use This Calculator

1

Select What You Know

Choose from the dropdown: Edge length (a), Volume (V), or Space diagonal (d). Select the value you already have.

2

Enter the Value

Input the known value in the input field. Make sure it's a positive number in consistent units.

3

Get All Results

Click "Calculate" to instantly get the edge length (a), volume (V), space diagonal (d), and surface area. All values are calculated from your input.

Formulas

Volume: V = a³

Edge length to volume

Space Diagonal: d = a√3

Edge length to diagonal (corner to opposite corner)

Surface Area: A = 6a²

Total area of all six faces

Where:

  • a = edge length of the cube
  • V = volume of the cube
  • d = space diagonal (from one corner to the opposite corner)
  • A = total surface area

Example 1: From Edge Length

Given: a = 5 units

V = a³ = 5³ = 125 units³

d = a√3 = 5 × √3 ≈ 8.66 units

A = 6a² = 6 × 5² = 150 units²

Example 2: From Volume

Given: V = 64 units³

a = ∛V = ∛64 = 4 units

d = a√3 = 4 × √3 ≈ 6.93 units

A = 6a² = 6 × 4² = 96 units²

Example 3: From Diagonal

Given: d = 10√3 units ≈ 17.32 units

a = d/√3 = (10√3) / √3 = 10 units

V = a³ = 10³ = 1000 units³

A = 6a² = 6 × 10² = 600 units²

About Cube Calculator: Find V, a, d

This cube calculator allows you to find any cube property (volume V, edge length a, or space diagonal d) from just one known value. A cube is a three-dimensional shape with six equal square faces, making it a perfect geometric solid.

When to Use This Calculator

  • Geometry Problems: Solve cube-related problems when you know one dimension
  • Architecture: Calculate cube dimensions from volume or diagonal measurements
  • Engineering: Determine material requirements when only one cube property is known
  • Packaging: Find cube dimensions for packaging or storage solutions
  • Mathematics Education: Teach students relationships between cube properties
  • 3D Design: Work with cube models in CAD or design software

Why Use Our Calculator?

  • ✅ Flexible Input: Start with edge, volume, or diagonal - we calculate the rest
  • ✅ Complete Results: Get all cube properties (V, a, d, and surface area) at once
  • ✅ Step-by-Step Display: See the formulas and calculations used
  • ✅ 100% Accurate: Uses precise mathematical relationships
  • ✅ Instant Calculations: No manual formula solving required
  • ✅ Completely Free: No registration required

Understanding Cube Relationships

All cube properties are mathematically related:

  • Volume (V): The amount of space inside = a³ (edge cubed)
  • Edge (a): The length of any side - all edges are equal in a cube
  • Space Diagonal (d): The longest distance between opposite corners = a√3
  • Surface Area (A): Total area of all 6 faces = 6a²
  • Face Diagonal: Diagonal of one square face = a√2

Real-World Applications

Storage: A storage container has a volume of 27 m³. Using this calculator with volume = 27, we find edge = 3 m, diagonal ≈ 5.20 m, and surface area = 54 m². This helps determine if items fit and how much material is needed for construction.

Architecture: A cube-shaped room has a space diagonal of 17.32 m. From diagonal = 17.32, we calculate edge = 10 m, volume = 1000 m³, and surface area = 600 m². Useful for room planning and material estimation.

Packaging: A cube box with 8 cm edges has volume = 512 cm³, diagonal ≈ 13.86 cm, and requires 384 cm² of material for all six faces. This calculator makes it easy to find any property from the others.

Frequently Asked Questions

What is a space diagonal?

A space diagonal is the longest line segment inside a cube, connecting two opposite vertices (corners) that don't share a face. Formula: d = a√3, where a is the edge length.

How do I find the edge length from volume?

Take the cube root of the volume: a = ∛V. For example, if V = 125, then a = ∛125 = 5. The calculator does this automatically when you select "Volume" as your input.

What's the difference between space diagonal and face diagonal?

Space diagonal (d = a√3) goes through the cube from corner to opposite corner. Face diagonal goes across one square face (d = a√2). Both are different measurements of a cube.

Can I calculate if I only know the surface area?

Not directly in this calculator, but you can: from surface area A, find edge a = √(A/6), then use edge as input. For example, if A = 150, then a = √(150/6) = √25 = 5.

Why does the space diagonal use √3?

Using the 3D Pythagorean theorem, the space diagonal is the hypotenuse of a right triangle with sides a, a, and a√2 (face diagonal). This gives d = √(a² + a² + (a√2)²) = a√3.

Are all cube edges equal?

Yes! By definition, a cube has all edges of equal length. This is what makes it a cube (not just a rectangular prism). If edges differ, it's a rectangular box, not a cube.