The Area Of A Parallelogram Calculator
Parallelogram area looks like rectangle area until you notice the sides are slanted, and using the slanted side instead of the height is the mistake almost everyone makes once.
Area
60
- Perimeter
- 34
- Height to base ratio
- 0.6
- Sine of the slant angle
- 0.8571
Values update as you type. This calculator covers the single scenario its formula assumes — see Common Mistakes for what it leaves out.
The formula this calculator uses
area = base x perpendicular height
- A
- Area enclosed, in square units
- b
- Base, the length of one parallel side
- h
- Perpendicular height between the parallel sides
How to check the result by hand
- 1
Pick one of the parallel sides as the base
Either pair works, as long as you then use the height measured between that pair. Mixing a base from one pair with a height from the other gives a meaningless answer.
- 2
Measure the perpendicular height
This is the straight up distance between the two parallel sides, not the length of the slanted edge. Drop a perpendicular from the top side to the base line and measure that.
- 3
Convert both to the same unit
Multiplication cannot combine metres with centimetres. Convert first, or the area will be out by a factor of a hundred.
- 4
Multiply base by height
Ten times six is sixty square units. There is no one half and no division, unlike the triangle formula the shape is often mistaken for.
- 5
Add the slanted side only if perimeter is wanted
Perimeter is twice the base plus the side, which for a base of ten and a side of seven is thirty four. Do not put the side into the area calculation.
For worked examples, common mistakes and the limits of this formula, read the full How To Calculate The Area Of A Parallelogram page.