Parallelogram Area Calculator

Calculate the area of a parallelogram instantly. Enter the base and perpendicular height for step-by-step solutions.

h = 5b = 8

What is the Area of a Parallelogram?

A parallelogram is a quadrilateral with two pairs of parallel sides. Its area is simply base times height (A = b × h), where the height is the perpendicular distance between the parallel sides—not the slant side length! This is the same formula as for rectangles because a parallelogram can be rearranged into a rectangle.

Area Formula

A = b × h

Base times perpendicular height. Do NOT use the slant side length!

Using Two Sides + Angle

A = a × b × sin(θ)

Where a and b are adjacent sides and θ is the angle between them.

Using Diagonals

A = ½ × d₁ × d₂ × sin(φ)

Where d₁ and d₂ are diagonals and φ is the angle between them.

Perimeter

P = 2(a + b)

Sum of all four sides (opposite sides are equal).

Examples

Basic: base 8, height 5

A = 8 × 5 = 40 square units = 40

With Angle: sides 6 and 10, angle 60°

A = 6 × 10 × sin(60°) = 60 × 0.866 ≈ 52 = ≈ 52

Rhombus: diagonals 8 and 6

A = ½ × 8 × 6 = 24 (diagonals are perpendicular in a rhombus) = 24

Tile Pattern: base 30cm, height 25cm

A = 30 × 25 = 750 cm² per tile = 750 cm²

Frequently Asked Questions

What is the formula for the area of a parallelogram?

The area of a parallelogram is A = base × height, where the height is the perpendicular distance between the two parallel bases—not the length of the slanted side.

Why is the area formula base × height, not base × side?

The slant side is longer than the height. If you 'cut' a triangle from one end and move it to the other, a parallelogram becomes a rectangle. That's why we use perpendicular height.

What is a rhombus?

A rhombus is a special parallelogram where all four sides are equal length. Its area can be calculated as A = ½ × d₁ × d₂ (half the product of diagonals) since diagonals are perpendicular in a rhombus.

Is a rectangle a parallelogram?

Yes! A rectangle is a parallelogram with all angles equal to 90°. All properties of parallelograms apply to rectangles, plus the additional right-angle property.

How do I find the height of a parallelogram?

If you know the area and base: h = A / b. Otherwise, if you know a side and an angle, use h = side × sin(angle) where the side is the slant side adjacent to the base.