Rectangle Area and Perimeter Calculator
Enter the length and width — get the area, perimeter and diagonal (by Pythagoras) all at once. Perfect for land, room or plot calculations.
Enter values — the result will show live here.
How to use
- Enter the length and width in the same unit (feet, meter etc).
- The area, perimeter and diagonal will all show in the result.
Note: Formulas: Area = length x width, Perimeter = 2(length + width), Diagonal = √(length² + width²). The result will be in the same unit you entered.
Frequently Asked Questions (FAQ)
What does the Rectangle Area Calculator give me?
Enter the length and width and get the area, perimeter and diagonal (by Pythagoras) all at once.
What units should I use?
Any unit works — centimetres, feet or metres — as long as length and width use the same one. The area comes out in square units.
Can I use it for a square?
Yes. Enter the same value for length and width.
Does it work for other shapes?
No, rectangles only. For regular polygons, use the Regular Polygon Calculator on this site.