Parallelogram Area Calculator
Find the area of a parallelogram two ways: from a base and its perpendicular height, or from two adjacent sides and the included angle. The sides-and-angle mode also returns the perimeter, while base-and-height gives the area alone because the slanted side length is unknown. Switch modes with a tap and read exact results as you type.
How to find the area of a parallelogram
- Choose a mode with the buttons: Base and height, or Sides and angle.
- In base-and-height mode, enter the base and the perpendicular height.
- In sides-and-angle mode, enter side A, side B, and the angle in degrees.
- Read the Area card, and the Perimeter card when you supply two sides.
- Press Copy result to grab the area and perimeter as text.
Examples
Base 8, height 5
base = 8, height = 5
area = 40, perimeter = not available
Sides 8 and 6 with a 30 degree angle
sideA = 8, sideB = 6, angle = 30 degrees
area = 24, perimeter = 28
Equal sides of 6 at a right angle
sideA = 6, sideB = 6, angle = 90 degrees
area = 36, perimeter = 24
Frequently asked questions
What is the formula for the area of a parallelogram?
In base-and-height mode the area equals the base times the perpendicular height. A base of 8 and a height of 5 give an area of 40 square units.
Can I find the area without the height?
Yes. Switch to sides-and-angle mode, where the area equals side A times side B times the sine of the angle between them. Sides of 8 and 6 with a 30 degree angle give an area of 24.
What is the perpendicular height, exactly?
It is the straight-line distance between the base and the opposite side, measured at a right angle to the base, not the length of the slanted side. Using a slanted side by mistake overstates the area.
Why is the perimeter sometimes not available?
Base and height alone do not reveal the slanted side length, so the perimeter cannot be found. Supply two sides and the angle instead and the tool returns the perimeter as well.
How is the perimeter calculated?
A parallelogram has two pairs of equal sides, so the perimeter equals two times the sum of side A and side B. Sides of 8 and 6 give a perimeter of 28.
Does the angle need to be in degrees?
Yes. Enter the angle between the two sides in degrees, from just above 0 up to just below 180. The tool converts it to radians internally before taking the sine.
What happens at a 90 degree angle?
At 90 degrees the sine is 1, so the parallelogram is a rectangle and the area equals side A times side B. Sides of 6 and 6 at 90 degrees give an area of 36 and a perimeter of 24.
Can I enter decimals or must values be whole?
Decimals are fine. Each field steps in tenths but accepts any positive value, and results are rounded to six decimal places so fractional measurements stay accurate.
Is anything I enter uploaded?
No. The geometry is computed by a pure function in your browser, so the dimensions you type never leave your device.
Learn more
- Two ways to measure a parallelogram
When to use base times height versus the sides-and-angle formula, and how the angle quietly controls a parallelogram's area.
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