Math

Rectangle Calculator

Calculate rectangle area, perimeter, diagonal, and dimensions from any two known values with step-by-step solutions.

Complete Rectangle Calculator

Calculate all properties of a rectangle from any two known values. Enter length and width, length and area, length and perimeter, or diagonal and length to get all measurements instantly.

Rectangle Formulas

A rectangle is a quadrilateral with four right angles. The key formulas are: Area = length × width, Perimeter = 2(length + width), and Diagonal = √(length² + width²). A square is a special rectangle where length equals width.

Rectangle Area Formula

A = l × w

How to Use This Calculator

1

2

3

4

5

Rectangle Calculator Applications

Room Planning

Calculate floor area, wall dimensions, and furniture placement.

Construction

Determine material quantities for rectangular surfaces.

Screen Sizing

Calculate display dimensions and aspect ratios.

Landscaping

Plan rectangular gardens, patios, and outdoor spaces.

Frequently Asked Questions

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. Our calculator detects when dimensions form a square.