What This Calculator Does
The Rectangular Solid Volume Calculator finds the cubic volume of any box-shaped object — also called a rectangular prism or cuboid. You enter three measurements (length, width and height) and the tool instantly multiplies them together to give the total space inside the shape. As a bonus, it also computes the total surface area, which is handy when you need to know how much material covers the outside.
The Inputs You Provide
- Length – the longest horizontal measurement of the box.
- Width – the shorter horizontal measurement (depth).
- Height – how tall the box stands.
Use the same unit for all three values (for example all in centimetres, inches or metres). The result comes out in that unit cubed — so metres give cubic metres (m³) and inches give cubic inches (in³).
The Formula Explained
Volume is calculated with the simple multiplication:
$$V = l \times w \times h$$The calculator also returns surface area using:
$$A = 2 \times (l \times w + l \times h + w \times h)$$The surface area adds up the six rectangular faces of the box: the top and bottom, the front and back, and the two sides.
Worked Example
Suppose you have a storage box that is 4 m long, 3 m wide and 2 m high.
- Volume = \(4 \times 3 \times 2 = \) 24 cubic metres (m³)
- Surface area = \(2 \times (4 \times 3 + 4 \times 2 + 3 \times 2) = 2 \times (12 + 8 + 6) = 2 \times 26 = \) 52 square metres (m²)
So the box holds 24 m³ of contents and has 52 m² of outer surface.
Frequently Asked Questions
Can I mix units like feet and inches?
No. Convert all three dimensions to the same unit first, or the answer will be wrong. The calculator simply multiplies the numbers you give it.
What's the difference between volume and surface area?
Volume is the space inside (cubic units), useful for capacity or shipping. Surface area is the outer covering (square units), useful for wrapping, painting or material costs.
Does the order of length, width and height matter?
No. Because multiplication is commutative, swapping the labels produces the same volume and the same surface area.
