How is the area of a parallelogram calculated?

Area = base × side × sin(angle), which equals base × height. The height is the side length times the sine of the included angle.

How are the two diagonals found?

They come from the law of cosines: d₁ = √(a² + b² − 2ab·cos(angle)) and d₂ = √(a² + b² + 2ab·cos(angle)), where a is the side and b is the base.

Is any data uploaded?

No — all calculations happen in your browser and nothing leaves your device.

Parallelogram Calculator

Area, height, perimeter and diagonals of a parallelogram.

Parallelogram calculator

Enter the base, the adjacent side and the included angle between them and this tool returns the area, height, perimeter and both diagonals of the parallelogram.

The area is base × side × sin(angle) and the diagonals follow the law of cosines. Everything is computed locally in your browser — nothing is uploaded.