Rhombus Area Calculator
A rhombus is a four-sided polygon with all sides of equal length. The rhombus is a type of parallelogram where opposite sides are parallel and opposite angles are equal. Rhombuses are often depicted as diamond shapes. This calculator can compute the area of a rhombus using two different methods. Method 1 uses the lengths of the two diagonals, which intersect at right angles. Method 2 uses the length of one side and an interior angle. The perimeter is calculated as four times the side length, since all sides of a rhombus are equal.
Rhombus formulas
Area = (diagonal1 * diagonal2) / 2
Area = side^2 * sin(angle)
Perimeter = 4 * side
Example calculation
For a rhombus with diagonals of 12 and 16 units, side length of 10, and angle of 60 degrees:
- Area (diagonals) = (12 * 16) / 2 = 192 / 2 = 96.00 square units
- Area (side and angle) = 10^2 * sin(60deg) = 100 * 0.866 = 86.60 square units
- Perimeter = 4 * 10 = 40 units
Rhombus area calculator: frequently asked questions
What is a rhombus?
A rhombus is a parallelogram with all four sides of equal length. It is sometimes called a diamond shape. A rhombus is defined by either its diagonals or by the length of one side and one of its angles.
What are the formulas for the area of a rhombus?
There are two common formulas. The first uses the two diagonals: Area = (d1 * d2) / 2. The second uses a side length and an angle: Area = a^2 * sin(angle), where a is the side length.
What is the relationship between the diagonals of a rhombus?
The diagonals of a rhombus bisect each other at right angles (90 degrees). This means they split each other exactly in half and meet at a right angle. This property is unique to rhombuses among parallelograms.
How are a rhombus and a square different?
A square is a special type of rhombus where all angles are 90 degrees. A regular rhombus has angles that are not 90 degrees. All squares are rhombuses, but not all rhombuses are squares.
What is the perimeter of a rhombus?
Since all four sides of a rhombus are equal in length, the perimeter is simply 4 times the side length: perimeter = 4 * a.
Official sources
- Wolfram MathWorld: Rhombus.
- ISO 80000-2: Mathematical signs and symbols.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.