A rectangular prism is the 3D shape behind every shipping carton, aquarium, and room volume estimate.
About this calculator
A rectangular prism is the 3D shape behind every shipping carton, aquarium, and room volume estimate. Multiply length × width × height for cubic capacity. Surface area counts all six faces: top and bottom (LW), front and back (LH), left and right (WH), each counted twice.
Use consistent units — centimetres give cubic centimetres (millilitres if you divide by 1000 for litres). A 10×4×3 box holds 120 cubic units and needs 164 square units of material if you wrap every face.
A cube is the special case L = W = H. For cylindrical tanks use the [[cylinder]] calculator; for general mixed solids try [[volume]] and [[surface-area]]. Link to [[rectangle]] for the base footprint area.
Common uses
- Shipping carton volume for courier weight-tier checks
- Room air volume for HVAC rough sizing
- Aquarium or tank capacity in litres (use cm inputs)
- Cardboard sheet area for a six-face box wrap
- School geometry — compare two boxes with equal volume
Frequently asked questions
What is the volume of a 10 × 4 × 3 box?
V = 10 × 4 × 3 = 120 cubic units. Surface area = 2(40 + 30 + 12) = 164 square units.
Is a cube a rectangular prism?
Yes. When L = W = H all faces are equal squares. The same formulas apply.
How do I convert cm dimensions to litres?
Compute volume in cm³, then divide by 1000. A 50×30×40 cm tank holds 60,000 cm³ = 60 litres.
Which faces does surface area include?
All six outer faces — both bases, both ends, and both sides. Open-top boxes need manual subtraction of one LW face.