Instantly find volume, surface area, and diagonal of any box
Dimensions
Results
Face Areas
Formulas
Use this rectangular prism calculator to instantly compute the volume, total surface area, lateral surface area, space diagonal, and individual face areas of any box or cuboid shape. Simply enter the length, width, and height — results update in real time. Ideal for packaging, shipping, construction, and geometry homework.
Volume = Length × Width × Height (V = L × W × H). For example, a box measuring 8 cm × 5 cm × 3 cm has a volume of 120 cm³.
Total surface area includes all six faces: 2(LW + LH + WH). Lateral surface area covers only the four side faces (excluding top and bottom): 2(LH + WH). This distinction matters for painting walls vs. flooring, for instance.
The space diagonal is the longest internal line connecting two opposite corners of the prism, calculated as √(L² + W² + H²). It represents the maximum object length that can fit diagonally inside the box.
Yes — simply enter equal values for length, width, and height. A cube is a special case of a rectangular prism where all three dimensions are the same.