Box Volume Calculator (Rectangular Prism)
By Santaji GadepatilinUpdated October 27, 2026
A box, or rectangular prism, has a volume equal to length × width × height. It is the everyday calculation behind packing, shipping and storage. This free box volume calculator solves for whichever value you leave blank and shows the formula and steps.
How to use the box volume calculator
Enter the length, width and height. You get the volume, the total surface area and the space diagonal. Change any unit — the results convert automatically.
Box volume formulas
V = l × w × h · S = 2(lw + lh + wh) · d = √(l² + w² + h²)
Common box sizes
| Box (cm) | Volume | Cubic feet |
|---|---|---|
| 30 × 20 × 15 | 9.0 L | 0.32 ft³ |
| 40 × 30 × 30 | 36.0 L | 1.27 ft³ |
| 45 × 45 × 45 | 91.1 L | 3.22 ft³ |
| 60 × 40 × 40 | 96.0 L | 3.39 ft³ |
| 60 × 45 × 45 | 121.5 L | 4.29 ft³ |
| 100 × 100 × 100 | 1000.0 L | 35.31 ft³ |
Shipping: volumetric weight
Couriers charge by actual or volumetric weight, whichever is higher:
Volumetric weight (kg) = L × W × H (cm) ÷ 5,000
A 60 × 40 × 30 cm box has a volumetric weight of 14.4 kg. Some carriers divide by 6,000 for road freight — check your courier.
Moving and storage
- A standard moving box is roughly 1.5–3 ft³.
- A storage unit 5 × 10 × 8 ft holds 400 ft³ (11.3 m³).
- A 20 ft shipping container has about 33 m³ of internal space.
Cube
For a cube with side s: V = s³, S = 6s², d = s√3.
Frequently asked questions
How do I calculate the volume of a box?
Multiply length × width × height. A 60 × 40 × 30 cm box holds 72,000 cm³, or 72 litres.
How do I convert cm³ to litres?
Divide by 1,000. 1,000 cm³ = 1 litre.
How many cubic feet is a box?
Measure in feet and multiply, or measure in inches, multiply and divide by 1,728.
What is the longest item that fits in a box?
The space diagonal, √(l² + w² + h²). For a 60 × 40 × 30 cm box it is 78.1 cm.