Rectangle Area Calculator – Length × Width
Calculate rectangle area, perimeter, and diagonal
Table of Contents
How to Use
- Enter the length of the rectangle
- Enter the width of the rectangle
- Click calculate to see the area
- View perimeter and diagonal as bonus results
Rectangle Area Formula
The area of a rectangle is calculated by multiplying its length by its width. This gives you the total space enclosed within the rectangle.
Formula: Area = Length × Width (A = l × w)
Examples
- Rectangle 5 × 3: Area = 15, Perimeter = 16, Diagonal ≈ 5.83
- Rectangle 10 × 4: Area = 40, Perimeter = 28, Diagonal ≈ 10.77
- Rectangle 8 × 8 (square): Area = 64, Perimeter = 32, Diagonal ≈ 11.31
Real-World Applications
- Flooring: Calculate how much carpet or tile you need
- Painting: Determine wall area for paint coverage
- Gardening: Plan garden bed sizes and layouts
- Construction: Calculate material requirements
- Interior design: Plan furniture placement and room layouts
Frequently Asked Questions
- What's the difference between area and perimeter?
- Area measures the space inside a rectangle (in square units), while perimeter measures the total distance around the outside edges (in linear units). For a 5×3 rectangle, area is 15 square units and perimeter is 16 units.
- Is a square a special type of rectangle?
- Yes! A square is a rectangle where all four sides are equal. The same formulas apply: Area = side², Perimeter = 4 × side, and Diagonal = side × √2.
- How do I find the length if I know the area and width?
- Divide the area by the width: Length = Area ÷ Width. For example, if the area is 24 and width is 4, then length = 24 ÷ 4 = 6.
- Why is the diagonal useful?
- The diagonal is useful for measuring across a rectangle, checking if corners are square (90°), and calculating the longest straight line that fits inside the rectangle.