Math & Statistics
Surface Area and Volume Calculator
Calculate surface area, volume, edge length, and space diagonal for a rectangular prism. The calculator uses surface area = 2(lw + lh + wh); volume = lwh. It returns more than one result so you can check the main answer against a useful secondary measure. Surface area measures covering material while volume measures enclosed space. Add waste, seams, thickness, and openings separately for real material estimates.
Check the displayed units, assumptions, and rounding before relying on the result.
Calculate and compare
Use the number box for precision or the slider for fast scenario testing.
Scenario results
Surface area
158 square units
Sum of all six faces.
Volume
120 cubic units
Length × width × height.
Space diagonal
9.8995 units
Corner-to-opposite-corner distance.
How the calculation works
Use consistent units and retain full precision until the final display step.
Worked example
Reproduce the displayed scenario, then change one assumption at a time.
Assumptions behind the result
- • Inputs use the units shown beside each control.
- • The displayed formula is applied without hidden market or demographic data.
- • Rounding occurs only for display; calculations keep full numeric precision.
- • Surface area measures covering material while volume measures enclosed space.
- • Add waste, seams, thickness, and openings separately for real material estimates.
Mistakes that change the answer
- • Mixing percentages with decimals or mixing incompatible units.
- • Relying on a rounded intermediate value instead of the full result.
- • Changing several assumptions at once instead of testing length separately.