What is a parallelogram calculator?
A parallelogram calculator computes the area and perimeter of a parallelogram from the dimensions you provide. A parallelogram is a four-sided shape (quadrilateral) with two pairs of parallel sides. You enter the base (one of the parallel sides), the height (perpendicular distance between the base and the opposite side), and the side length (the other pair of sides). The calculator gives you area = base × height and perimeter = 2 × (base + side). No sign-up or download is required; the tool runs in your browser and is useful for geometry homework, design, and any task involving parallelograms.
Parallelograms include rectangles, squares, and rhombuses as special cases. They appear in tilings, graphics, and many geometry problems. Knowing the area helps with material coverage; the perimeter helps with borders and framing. This free parallelogram calculator gives you area and perimeter from base, height, and side, in whatever units you use—meters, feet, inches—as long as you keep units consistent. Height must be measured perpendicular to the base, not along the slanted side.
How to use this parallelogram calculator
Enter the base and height of your parallelogram for area. Base is one of the two parallel sides; height is the perpendicular distance from that base to the opposite side. For perimeter, you also need the side length (the length of the other pair of sides). You can enter all three: base, height, and side. Area uses only base and height; perimeter uses base and side. If you leave side blank, the calculator uses the base for side (so perimeter = 4 × base, as in a rhombus with equal sides). Use positive numbers. Results appear as soon as the inputs are valid: area in square units, perimeter in the same linear unit as your dimensions.
Parallelogram area formula
The area of a parallelogram is A = base × height, where the height is the perpendicular distance from the base to the opposite side. So if the base is 8 units and the height is 5 units, the area is 8 × 5 = 40 square units. This is the same formula as for a rectangle: think of a parallelogram as a rectangle “sheared” so that the top slides sideways; the base and perpendicular height stay the same, so the area does too. Do not use the slanted side length as height—height must be perpendicular to the base. The parallelogram calculator applies this formula so you get an accurate area from base and height.
Perimeter of a parallelogram
The perimeter of a parallelogram is the total distance around it. A parallelogram has two pairs of equal sides: two sides of length “base” and two sides of length “side.” So P = 2 × (base + side). For base 8 and side 6, the perimeter is 2 × (8 + 6) = 28 units. Perimeter is a length, so it uses the same unit as base and side. Use it when you need the length of fencing around a parallelogram plot, the border of a parallelogram panel, or the trim around a parallelogram frame. The calculator gives you the perimeter as soon as you enter valid base and side.
Base, height, and side
The base is any one of the four sides; we usually choose the horizontal or longer one for convenience. The height is always the perpendicular distance from the base to the opposite side—not the length of the slanted edge. You can measure height by dropping a perpendicular from the opposite side to the line containing the base. The side (or “other” side) is the length of the pair of sides that are not the base. In a rectangle, the side equals the height; in a slanted parallelogram, the side is longer than the height. This calculator needs base and height for area, and base and side for perimeter. If you only know base and side (e.g. from a diagram), you cannot find area without the height or an angle; you can still find the perimeter.
Special cases: rectangle, square, rhombus
A rectangle is a parallelogram with right angles; the side equals the height, so area = base × height is length × width and perimeter = 2(length + width). A square is a parallelogram with all sides equal and right angles; use base = side for perimeter. A rhombus is a parallelogram with all four sides equal; area is still base × height (height is perpendicular), and perimeter = 4 × side. You can use this parallelogram calculator for rectangles and squares by entering length and width as base and height (and side = height for rectangle, or base = side for square perimeter). The formulas are the same; the shape is a special parallelogram.
Applications of parallelogram calculations
Parallelogram area and perimeter are used in geometry, design, and construction. In education, the parallelogram is a core shape when studying quadrilaterals and area. In design and graphics, parallelograms appear in tilings and perspective. In construction, some panels and plots are parallelogram-shaped. This parallelogram calculator gives you quick, accurate results for area and perimeter. Always measure height perpendicular to the base, and keep units consistent: same unit for base, height, and side; area in square units; perimeter in the same linear unit.
Summary
This parallelogram calculator finds the area and perimeter of a parallelogram from the base, height, and side. Enter base and height for area (base × height), and base and side for perimeter (2 × (base + side)). The tool is free, runs in the browser, and requires no account. Use it for homework, design, or any parallelogram shape. Remember: height is the perpendicular distance to the base, not the slanted side. Keep units consistent for accurate results.