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Geometry

Cuboid Surface Area Calculator

Add all six faces of a closed rectangular box.

Let’s calculate.

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Your result
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Rounded to up to 2 decimal places.

Measurement units

Changing the input unit also selects its matching result unit. Choose another result unit to convert the answer. Input numbers stay unchanged.

SI prefixes and selected international / customary units. Coverage: SI and selected current customary units. Historical units are excluded.

See what you’re calculating

lengthheightwidth
Surface area = 2 × (length × width + length × height + width × height)

Add all six faces of a closed rectangular box.

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THE IDEA, SIMPLY

How it works

Add all six faces of a closed rectangular box.

FORMULA

Surface area = 2 × (length × width + length × height + width × height)

A worked example

A 5 m × 3 m × 2 m box has surface area 62 m².

Formula & detailed explanation

All dimensions nonnegative. Includes the top and bottom.

Calculations use decimal arithmetic with 40 significant digits internally. Choose 0–8 decimal places for the displayed result. Trailing zeros are omitted. Rounding affects only the displayed and copied result; very small values may round to zero. Accepted inputs have up to 100 characters and magnitudes from 10⁻¹⁰⁰ to 10¹⁰⁰, plus zero.

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