Enter the known angle into the calculator to determine the unknown angle of a parallelogram. This calculator can also evaluate any of the variables given the others are known.

Parallelogram Angle Formula

The following formula is used to calculate the angle of a parallelogram.

A = 180 - B


  • A is the angle you are trying to find (degrees) B is the known angle (degrees)

To calculate the angle of a parallelogram, subtract the known angle from 180 degrees. This is because the sum of the angles in a parallelogram is always 180 degrees.

What is a Parallelogram Angle?

A parallelogram angle refers to one of the four angles formed by the intersection of the sides of a parallelogram. In a parallelogram, opposite angles are equal (or congruent) and adjacent angles are supplementary, meaning they add up to 180 degrees. The sum of the interior angles of a parallelogram is always 360 degrees.