Area of a rhombus: in short
Multiply the two diagonals and divide by 2: a rhombus with diagonals of 6 m and 4 m has an area of 6 × 4 ÷ 2 = 12 m². If you know the base and height, the area is their product.
The formulas
Area = long diagonal × short diagonal ÷ 2. With a base b and height h the area is b × h, because a rhombus is a parallelogram with four equal sides. The diagonals cross at right angles and cut each other in half.
Examples from the diagonals
| Long diagonal | Short diagonal | Area | Side |
|---|---|---|---|
| 4 m | 2 m | 4 m² | 2.24 m |
| 5 m | 3 m | 7.5 m² | 2.92 m |
| 6 m | 4 m | 12 m² | 3.61 m |
| 8 m | 6 m | 24 m² | 5 m |
| 10 m | 8 m | 40 m² | 6.4 m |
The side and the perimeter
The side is the square root of (d ÷ 2)² + (e ÷ 2)²: with diagonals of 6 and 4 m it is 3.61 m, and the perimeter (4 sides) is 14.42 m.
Rhombus shapes at home
A floor with diamond tiles, a flower bed or a deck with cut corners all take this shape. Measure the two diagonals from corner to corner; in the editor you can draw the rhombus with those lengths.
Figure 1. One floor of 7.5 × 5 m. The rooms add up to 37.5 m².
About this page · Written by the Squaremetry team. Last checked on 7 October 2026. Found a mistake? Send us a message.