Math Tools
Rectangle Perimeter, Area, and Diagonal Calculator
Rectangle Perimeter, Area, and Diagonal Calculator
To compute the area, perimeter, and diagonal of a rectangle, fill in the form below.
Rectangle formulas
- Perimeter: add width and height, then multiply by two (2 × (w + h)).
- Area: multiply width by height (w × h).
- Diagonal: use the Pythagorean theorem √(w² + h²).
Keep the same measurement unit for width and height to keep your results consistent.
