What is the area of a rectangle?

Area = length × width. For a 5×3 rectangle, area = 15 square units.

What is the perimeter of a rectangle?

Perimeter = 2(length + width). For a 5×3 rectangle, perimeter = 2(5+3) = 16 units.

What is the diagonal of a rectangle?

Diagonal = √(length² + width²), using the Pythagorean theorem.

What's the difference between a rectangle and a square?

A square is a special rectangle where all sides are equal (length = width).

Rectangle Calculator

Calculate area, perimeter, and diagonal of a rectangle.

Unit of Measurement

Length

Width

Preview

Area

0 cm²

A = l × w = 8 × 5 = 0

Perimeter

0 cm

2(l + w)

Diagonal

0 cm

√(l² + w²)

Documentation

Understanding Rectangles

A rectangle is a 4-sided polygon with opposite sides equal and all angles 90°. Area = l×w, Perimeter = 2(l+w).

Area

Perimeter

Diagonal

Frequently Asked Questions

How to Use

About the Rectangle Calculator

What it calculates

This rectangle calculator solves mathematical and statistical problems using standard formulas. Calculate area, perimeter, and diagonal of a rectangle.

When to use it

Use for homework, data analysis, exam prep, or quick verification of manual calculations.

Example

Adjust the inputs above to model your specific scenario with the Rectangle Calculator.

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