Parallelogram Area Calculator
Compute parallelogram area from base and perpendicular height. Enter the adjacent side when you also want perimeter. Area uses A = base × height, not the slanted side alone.
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How to find parallelogram area
- Enter the base length along one pair of parallel sides. The default base is 5.
- Enter the perpendicular height from that base to the opposite side. The default height is 3.
- Optionally enter the adjacent side length if you want perimeter. The default side is 4.
- Read area as base times height. With side filled, also read perimeter 2(base + side).
- Keep height perpendicular to the base. A slanted side length alone does not replace height.
Parallelogram area
Base times perpendicular height for a four-sided figure with opposite sides parallel
| Area formula | A = base × height (height is perpendicular) |
|---|---|
| Perimeter formula | P = 2(base + adjacent side) when side is known |
| Default example | Base 5, height 3 give area 15; side 4 gives perimeter 18 |
| Height rule | Use the altitude to the chosen base, not the slanted side |
| Special cases | Rectangle and rhombus are parallelograms with extra constraints |
| Privacy | Arithmetic runs in this tab. CZNull does not receive the numbers. |
What parallelogram area measures
A parallelogram has two pairs of parallel sides. Area equals the product of one base and the perpendicular distance to the opposite side. Base 5 and height 3 give area 15 in matching length units. The slanted side can differ from the height.
How this page computes area and perimeter
Area = base × height. Both must be positive finite numbers. When you supply a positive adjacent side, perimeter = 2(base + side). Without a usable side, the page still shows area and asks for the side to total perimeter. IEEE floating point applies in this browser.
Height versus adjacent side
Height is the altitude. The adjacent side is the other edge length used for perimeter. Multiplying base by the slanted side alone does not give area unless the angle is 90°. For a right angle, the figure is a rectangle and height equals that side.
Use cases
Classroom homework, plot sketches with parallel boundaries, and sheet layouts where you know base and altitude. Surveyors who only know sides and an included angle should convert to height first; this form does not take an angle input.
Limits
Plane geometry only. No 3D prism volume. No unit conversion between feet and meters. Invalid or non-positive base or height appear in the status line. See the disclaimer.