Parallelogram Area Calculator
The area of a parallelogram — base times perpendicular height, exactly like a rectangle.
Cut the triangle off one end of a parallelogram and slide it to the other, and you have a rectangle of the same base and height.
How the parallelogram area calculator works
Cut the triangle off one end of a parallelogram and slide it to the other, and you have a rectangle of the same base and height. That is why the area is simply base × height, and why the sloping side does not enter into it at all. The slant only matters for the perimeter, which is 2 × (base + side).
Formula: square a²; rectangle ab; triangle ½bh; circle πr²; parallelogram bh; trapezoid ½(a+b)h; ellipse πab
Worked examples
| Inputs | Area | Note |
|---|---|---|
| Base 10, height 6 | 60 | area 60 |
| A steeply leaning shape | 24 | area 24 — the lean does not change it |
| Base 5, height 5 | 25 | 25, the same as a square of side 5 |
FAQFrequently asked questions
What is the area of a parallelogram?
Base × perpendicular height. The sloping sides are irrelevant to the area.
Why is it the same as a rectangle?
Because you can cut a triangle off one end and slide it to the other, turning it into a rectangle of the same base and height.
Which measurement is the height?
The perpendicular distance between the two parallel sides — not the length of the slanted edge.
What is the perimeter?
Twice the base plus twice the sloping side.
Is a rectangle a parallelogram?
Yes — a rectangle is a parallelogram whose angles happen to be right angles.
Where these figures come from
- NIST Digital Library of Mathematical Functions — reference definitions for elementary and special functions
- Wolfram MathWorld — definitions and formulas for every topic on this page
- NIST/SEMATECH e-Handbook of Statistical Methods — the statistical formulas (mean, variance, z, confidence intervals, sample size)
- Common Core State Standards — Mathematics — the terms and methods taught in US schools
Last checked: September 2026. Formulas are fixed by mathematics and do not change with tax years or regulations.