l = length
w = width
h = height
d = diagonal
S = surface area
V = volume
Enter any 3 variables for a rectangular prism into this online calculator to calculate the other 3 unknown variables. A cube is a special case where l = w = h for a rectangular prism.
* Units: Note that units are shown for convenience but do not affect the calculations. The units are in place to give an indication of the order of the results such as ft, ft2 or ft3. For example, if you are starting with mm and you know r and h in mm, your calculations will result with s in mm, V in mm3, L in mm2, T in mm2, B in mm2 and A in mm2.
A cube is a special case where l = w = h. So you can find the volume of a cube or surface area of a cube by setting these values equal to each other.
1. Given the length, width and height find the volume, surface area and diagonal of a rectangular prism
2. Given the surface area, length and width find the height, volume and diagonal of a rectangular prism
3. Given the volume, length and width find the height, surface area, and diagonal of a rectangular prism
4. Given the diagonal, length and width find the height, volume and surface area of a rectangular prism
For more information on cuboids see: Weisstein, Eric W. "Cuboid." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/Cuboid.html