Parallelogram Area Calculator
Find the area of any parallelogram from a base and its perpendicular height — area = base × height — in whatever units you measure in.
One simple formula
The base times the perpendicular height gives the area of every parallelogram, whatever its slant.
Use the right height
The height must be measured at a right angle between the parallel sides — not along a slanted side, or the area comes out too large.
What is the area of a parallelogram?
The space inside the four sides
The area of a parallelogram is the amount of flat space enclosed by its four sides, where opposite sides are parallel and equal in length. You only need two measurements: a base (one of the parallel sides) and the perpendicular height to that base. The area is simply the product of the two — area = base × height. The result is in the square of whatever unit you measure in, so metres give square metres and inches give square inches.
A parallelogram can be cut along a vertical line and rearranged into a rectangle with the same base and height. That is why its area equals base times height — exactly the same as the rectangle it rearranges into. There is no halving here, which is the key difference from a triangle.
area = base × heightThe base can be either pair of parallel sides; the height is always the straight-line distance between those two parallel sides, measured at a right angle. Both base-and-height pairings give the same area, so you simply pick the pair that is easiest to measure.
Suppose a parallelogram has a base of 8 and a perpendicular height of 5.
Multiply base by height
Multiply the two measurements: 8 × 5 = 40.No halving needed
Unlike a triangle, a parallelogram fills the whole box, so there is nothing to divide.Read the area
The parallelogram covers 40 square units — square metres if you measured in metres, square feet if in feet.
The number you get is an area, so it is always expressed in square units of whatever you entered: a base and height in metres produce square metres, while feet produce square feet. The single most common mistake is using a slanted side instead of the perpendicular height — that always overstates the area, because the slanted side is longer than the true right-angle distance between the parallel sides. If your figure looks too big, check that the height really meets the base at a right angle. A rectangle is simply a parallelogram with right angles, so the same base × height formula applies to it unchanged. It is also worth knowing that a parallelogram is exactly twice the area of a triangle that shares the same base and height — the triangle formula just adds a halving step. Real-world uses are everywhere: land plots and slanted garden beds, tiled floors and roof panels, structural engineering, and graphic design layouts.
The formula is exact; the care is all in the measurement.
Measure the perpendicular height
This calculator assumes the height you enter is the true perpendicular distance between the parallel sides, measured at a right angle. Using the length of a sloping side instead will overstate the area. The tool is also unit-agnostic — keep the base and height in the same unit, and read the result as that unit squared. The same base × height rule covers rectangles and squares, since they are just parallelograms with right angles.