Just type the sides of the rectangle below and click Calculate Area. Use a period or comma as the decimal separator.
Rectangle Area Calculator
Result:
How to use the calculator
- Type the Length (longer side) of the rectangle.
- Type the Width (shorter side) of the rectangle.
- Select the unit of measurement.
- Click Calculate Area to see the result.
Rectangle area formula
The area of a rectangle is calculated by multiplying the length by the width:
A = a × b
Where a is the length and b is the width. The result is in square units: cm², m², etc.
Practical examples
| Length (a) | Width (b) | Area (A = a × b) |
|---|---|---|
| 8 m | 5 m | 40 m² |
| 12 cm | 7 cm | 84 cm² |
| 6.5 m | 3.2 m | 20.8 m² |
| 10 mm | 4 mm | 40 mm² |
| 2 km | 1.5 km | 3 km² |
Frequently asked questions
What is the formula for the area of a rectangle?
The area of a rectangle is A = a × b, where a is the length and b is the width. For example, 8 m × 5 m = 40 m².
How do you calculate the area of a rectangle?
Multiply the length by the width. Example: a rectangle 8 m × 5 m has area A = 8 × 5 = 40 m².
What is the difference between area and perimeter of a rectangle?
The area (A = a × b) measures the internal space in square units. The perimeter (P = 2 × (a + b)) measures the total boundary in linear units.
Is a square a special case of a rectangle?
Yes. When a = b, the formula A = a × b becomes A = a², which is the formula for the area of a square.
Can I use a comma instead of a decimal point?
Yes. This calculator accepts both a comma and a period as the decimal separator.
See also…
