How to use the rectangular prism calculator
Find volume, surface area and diagonal of a box. Enter length, width, height in the fields above; the volume, surface area, space diagonal are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- l — Length
- w — Width
- h — Height
Worked example
With length = 5, width = 4, height = 3, the calculator gives volume ≈ 60; surface area ≈ 94; space diagonal ≈ 7.071068.
Frequently asked questions
What is the formula for the rectangular prism calculation?
Volume = l × w × h. Surface area = 2 × (l × w+l × h+w × h). Space diagonal = √(l × l+w × w+h × h). Here l is length, w is width, h is height.
What inputs do I need for the rectangular prism (box) calculator?
You need length, width, height. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.