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math

Rectangle Calculator

Calculate the area and perimeter of a rectangle from its width and height, with a labeled diagram.

Area (square units)
40
Perimeter (units)
26
Diagram

How it works

  1. 1Enter the rectangle’s width and height.
  2. 2Read the area (width × height) and perimeter instantly.
  3. 3Check the labeled diagram to confirm your dimensions.

Use cases

  • Measure flooring, paint, or fabric coverage.
  • Find the perimeter for fencing or framing.
  • Check homework on rectangle area and perimeter.

Frequently asked questions

How do you find the area of a rectangle?

Multiply width by height. For example, an 8 × 5 rectangle has an area of 40 square units.

How do you find the perimeter?

Add all four sides, which equals 2 × (width + height). An 8 × 5 rectangle has a perimeter of 26 units.

What units does this use?

Whatever unit you enter. If your sides are in metres, the area is in square metres and the perimeter in metres.

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