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Calculate volume, surface area and space diagonal of a rectangular prism.
Calculate volume, surface area and space diagonal of a rectangular prism.
length=8
width=5
height=3Volume: 120 cubic units
Formula: V = length × width × height
Substitution: 8 × 5 × 3 = 120
Surface area: 158 square units
Formula: A = 2 × (length × width + length × height + width × height)
Substitution: 2 × (40 + 24 + 15) = 158
Diagonal: 9.899494936612 units
Formula: d = √(length² + width² + height²)
Substitution: √(64 + 25 + 9) = √98 = 9.899494936612Paste content, enter parameters or choose the files you need in “Length, width and height”.
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Review the result under “Prism measurements”, then copy or download it after checking the output.
Result guide
Enter three positive side lengths in one shared unit. The calculator returns volume in cubic units, total surface area in square units, and the corner-to-corner space diagonal in the original length unit.
Volume is V = length × width × height. Total surface area is A = 2(lw + lh + wh). The space diagonal follows the three-dimensional Pythagorean theorem: d = √(l² + w² + h²).
For length 8, width 5 and height 3, volume is 120 cubic units. Surface area is 2 × (40 + 24 + 15) = 158 square units, and the diagonal is √98 ≈ 9.899 units.
Use the same unit for all three inputs. This tool models a right rectangular prism with perpendicular faces; it does not handle rounded corners, wall thickness, open boxes, packing efficiency or material waste.
Multiply length by width by height. With 8, 5 and 3, the volume is 8 × 5 × 3 = 120 cubic units.
It is the straight line between opposite corners through the interior of the prism, calculated as √(length² + width² + height²).
No. Convert every side to one common unit before calculating so the area and volume units remain meaningful.
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