Rectangle Calculator

Calculate area, perimeter, and diagonal of any rectangle. Enter length and width to get instant results with multiple unit support.

The longer side of the rectangle

The shorter side of the rectangle

Area = Length * Width\nPerimeter = 2(Length + Width)\nDiagonal = sqrt(Length^2 + Width^2)\nAspect Ratio = Length / Width
Example 1 (Room Size):\nLength = 12 ft\nWidth = 10 ft\n\nArea = 12 * 10 = 120 ft^2\nPerimeter = 2(12 + 10) = 44 ft\nDiagonal = sqrt(144 + 100) = sqrt244 = 15.62 ft\n\nExample 2 (Garden Bed):\nLength = 8 m\nWidth = 3 m\n\nArea = 8 * 3 = 24 m^2\nPerimeter = 2(8 + 3) = 22 m\nDiagonal = sqrt(64 + 9) = sqrt73 = 8.54 m

What is the formula for the area of a rectangle?

The area of a rectangle is calculated as: Area = Length * Width. For example, a rectangle with length 10 cm and width 5 cm has an area of 10 * 5 = 50 cm^2. Area is always measured in square units.

How do I calculate the perimeter of a rectangle?

Perimeter is the total distance around the rectangle: Perimeter = 2(Length + Width) or Perimeter = 2L + 2W. For a 10*5 cm rectangle, perimeter = 2(10 + 5) = 30 cm.

What is the diagonal of a rectangle?

The diagonal is the distance across the rectangle from one corner to the opposite corner. It is calculated using the Pythagorean theorem: Diagonal = sqrt(Length^2 + Width^2). For a 3*4 rectangle, diagonal = sqrt(9 + 16) = 5.

What is the difference between a rectangle and a square?

A square is a special type of rectangle where all four sides are equal (Length = Width). All squares are rectangles, but not all rectangles are squares. A rectangle has two pairs of equal sides.

What are practical uses for rectangle calculations?

Common applications include: measuring room dimensions, calculating flooring or carpet needs, sizing picture frames, determining wall areas for painting, planning garden beds, calculating tile requirements, and any construction or design work involving rectangular shapes.