Rectangle Calculator
Calculate area, perimeter and diagonal of a rectangle from length and width.
About Rectangle Calculator
A rectangle's area is length × width, its perimeter is 2(l+w), and its diagonal follows the Pythagorean theorem.
Formulas
Area
A = l × w
- l
- Length
- w
- Width
Diagonal
d = √(l² + w²)
- l
- Length
- w
- Width
Worked example
With the default values below, Rectangle Calculator returns Area of 60.0000. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Lengthminimum 0 units
- 10 units
- Widthminimum 0 units
- 6 units
Results
- Area
- 60.0000 sq units
- Perimeter
- 32.0000 units
- Diagonal
- 11.6619 units
Step by step
- 1Area= 60
- 2Perimeter= 32
- 3Diagonal= 11.6619
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
Is a square a special rectangle?
Yes — a square is a rectangle where length equals width.
How many diagonals does a rectangle have?
Two, and they are equal in length and bisect each other.