Area of Rectangle Calculator
Calculate the area, perimeter, and diagonal of any rectangle by entering its length and width. This fundamental geometry calculator provides instant results for one of the most common shapes in construction, design, and everyday math.
A rectangle is a four-sided polygon with four right angles (90 degrees). Opposite sides are equal in length and parallel. The key formulas for a rectangle are:
Rectangle Formulas:
- Area: A = length x width
- Perimeter: P = 2 x (length + width)
- Diagonal: d = sqrt(length^2 + width^2)
The diagonal formula comes from the Pythagorean theorem, since the diagonal divides the rectangle into two right triangles. A square is a special case of a rectangle where the length equals the width.
Rectangle calculations are essential in real estate (room areas, lot sizes), construction (flooring, painting, fencing), interior design (furniture placement), agriculture (field areas), and manufacturing (material cutting). Understanding these formulas helps with cost estimation, material planning, and spatial optimization.