Rhombus Calculator

Calculate area, side length, perimeter, and angles of a rhombus from its diagonals.

This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.

Can't find what you need?

Request a Tool

How to Use the Rhombus Calculator

Enter the lengths of both diagonals and the calculator computes the area, side length, perimeter, and interior angles.

  1. Enter diagonal 1 (p). The length of the first diagonal.
  2. Enter diagonal 2 (q). The length of the second diagonal.
  3. Read the results. Area is the primary result. Side length, perimeter, and angles appear below.

Area = (p * q) / 2. Side = sqrt((p/2)^2 + (q/2)^2). Perimeter = 4 * side.

About Rhombuses

A rhombus is a quadrilateral with all four sides equal in length (an equilateral quadrilateral). Its diagonals bisect each other at right angles. The area equals half the product of the diagonals. A square is a special rhombus where all angles are 90 degrees. Rhombuses appear in diamond patterns, tilework, and kite designs. They are also a special case of parallelogram, so opposite angles are equal.

Frequently Asked Questions

What is the area of a rhombus?

Area = (d1 * d2) / 2, where d1 and d2 are the lengths of the two diagonals. For diagonals of 10 and 8, the area is 40.

How do you find the side length of a rhombus from its diagonals?

Since the diagonals bisect each other at right angles, each side is the hypotenuse of a right triangle with legs d1/2 and d2/2. So side = sqrt((d1/2)^2 + (d2/2)^2).

Is a square a rhombus?

Yes. A square is a rhombus where all angles are 90 degrees. It is also a rectangle. This makes it both a rhombus and a rectangle simultaneously.