Parallelogram Calculator

About this calculator

A parallelogram’s area is base times height (A = b × h), where height is the perpendicular distance between the two parallel bases — not the length of the slanted side. If you only know the two side lengths and the angle between them, the equivalent formula A = a × b × sin(θ) gives the same result without needing to find the perpendicular height separately. Perimeter, as with any quadrilateral, is simply twice the sum of the two distinct side lengths: P = 2(a + b).

The a × b × sin(θ) form is more than a classroom curiosity — it’s exactly the magnitude of the cross product of two vectors, so physicists and engineers use it to compute torque, angular momentum, and the area swept by two force or displacement vectors. Land surveyors and architects use the base-times-height form to calculate the area of parallelogram-shaped plots and structural panels, since irregular quadrilaterals are frequently approximated or decomposed into parallelograms for quick area estimates.

Enter the base, side length and height (or the angle between sides), and this calculator returns both the area and the perimeter of your parallelogram.