Rectangle Calculator
Enter a rectangle’s length and width to find its area, perimeter and diagonal.
units
units
32
11.6619
Formula
Examples
| Input | Result |
|---|---|
| length = 10, width = 6 | Area = 60, Perimeter = 32, Diagonal ≈ 11.6619 |
About this calculator
A rectangle is a four-sided polygon (quadrilateral) where every interior angle is a right angle and opposite sides are equal in length. Its area is simply length multiplied by width, while the perimeter is the total distance around the shape.
The diagonal connects opposite corners and is found with the Pythagorean theorem, since it forms the hypotenuse of a right triangle made by the length and width. These three measurements cover most practical needs in construction, flooring, framing and design.
Frequently asked questions
Multiply the length by the width. For example, a rectangle 10 by 6 units has an area of 60 square units.
Use the Pythagorean theorem: diagonal = √(length² + width²), because the diagonal is the hypotenuse of a right triangle formed by the two sides.
The calculator is unit-agnostic. Whatever unit you enter (cm, m, ft, in), the area is in square units and the perimeter and diagonal share the same linear unit.
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