Calculate area, perimeter, and diagonal length of a rectangle.
The Rectangle Area Calculator is a basic geometric tool designed to calculate the area, perimeter, and diagonal of a rectangle. A rectangle is a four-sided polygon (quadrilateral) with four right angles (90 degrees). The opposite sides of a rectangle are parallel and equal in length, commonly referred to as the width (w) and length (l). Rectangles are the most common shapes in construction, screen displays, and layout designs.
The area (A) of a rectangle represents the two-dimensional space within its boundaries. It is calculated using the formula: A = l × w. The perimeter (P) represents the total boundary length, calculated as the sum of all four sides: P = 2(l + w). The diagonal (d), which is the straight-line distance between opposite corners, can be solved using the Pythagorean theorem since the length, width, and diagonal form a right-angled triangle: d = √(l² + w²).
In daily life, rectangle area calculations are used for estimating flooring, buying rugs, ordering windows, and checking land plot sizes. In digital technology, screen resolutions (like 1920x1080 pixels) represent rectangular pixel areas. The rectangle area calculator provides fast, exact answers, eliminating manual math errors and helping users plan spaces, buy materials, and verify school math worksheets.
Rectangle Calculations
A rectangle is a quadrilateral with four right angles.
- Area (A):
A = l × w - Perimeter (P):
P = 2 × (l + w) - Diagonal (d):
d = √(l² + w²)
How it Works & Formula
Calculates the area, perimeter, and diagonal line length of a rectangle.
Practical Examples
A room measuring 12 feet by 15 feet needs 12 × 15 = 180 sq ft of carpet.
Frequently Asked Questions
Is a square a rectangle?
Yes, a square is a special type of rectangle where all four sides are equal in length.