Rectangle Area Calculator

Calculate the area, perimeter, and diagonal of a rectangle.

Last updated: June 2026 | By Patchworkr Team

Rectangle Properties

Length

Width

Math check: area = length x width

Result

Enter positive dimensions to compute the rectangle.

Formulas

area = length x width

perimeter = 2(length + width)

diagonal = sqrt(length^2 + width^2)

A rectangle with length 12 and width 8 has area 96 and perimeter 40.

Its diagonal is sqrt(12^2 + 8^2) = sqrt(208) = 14.422205.

A rectangle has four right angles and opposite sides of equal length.

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