How do I find the perimeter of a rhombus?

Find one side length, then multiply it by four because all rhombus sides are equal.

Can diagonals determine the perimeter?

Yes. The calculator treats half of each diagonal as the legs of a right triangle and recovers the side length.

Is a square a rhombus?

Yes. A square is a rhombus with right angles, so the same perimeter rule applies.

Rhombus Perimeter Calculator

Calculate rhombus perimeter from side length, diagonals, side and height, or side and area, with unit conversion and validation.

Known values

Unit

Side (m)

Use this when any side length is known.

Rhombus perimeter from the information you have

English search results treat a rhombus as a four-sided figure with equal sides. The main task is usually fast perimeter from one side, with extra modes for diagonals or area when the side is not given directly.

Known values	What is recovered	Output
Side length	Side is already known	Perimeter
Two diagonals	Side from half-diagonals	Perimeter
Side and height	Area for checking	Perimeter
Side and area	Height for checking	Perimeter

Rhombus formulas

P = 4 a

P is perimeter; a is side length.

a = (\frac{d _{1}}{2})^{2} + (\frac{d _{2}}{2})^{2}

d_1 and d_2 are the diagonals.

A = a \cdot h

A is area; h is height.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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