Trapezoid Area Calculator

Find the area of a trapezoid from its two parallel sides and height, plus the median and isosceles leg and perimeter.

Measured at right angles to the parallel sides, not along a slanted side.
Area
32
Median (midsegment)
8
Leg length, if isosceles
4.4721
Assumes both slanted sides are equal.
Perimeter, if isosceles
24.944

Estimate generated with SortedSums: https://sortedsums.com/trapezoid-area-calculator/. For informational purposes only; verify before relying on it.

How it’s calculated

A trapezoid (trapezium in British English) has two parallel sides, the bases a and b. Its area is the average of the bases times the perpendicular height.

Area = ½ × h × (a + b) Median m = (a + b) ÷ 2 Isosceles leg = √(h² + ((a − b) ÷ 2)²)

Example: bases 10 ft and 6 ft with height 4 ft give Area = ½ × 4 × 16 = 32 ft². If isosceles, each leg is √(16 + 4) ≈ 4.47 ft and the perimeter is about 24.94 ft.

Frequently asked questions

What is the formula for the area of a trapezoid?

A = ½h(a + b): add the two parallel sides, multiply by the height, and halve it.

Which measurement is the height?

The perpendicular distance between the two parallel sides. A slanted side is longer than the height unless it meets the bases at 90°.

Can I use this for a sloped yard or lot?

Yes, if the lot has two parallel edges. For irregular four-sided lots with no parallel sides, split them into two triangles and use the triangle calculator.

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Sources

Formulas are taken from the free public references above. Results are provided “as is” for informational and educational purposes only. See our disclaimer.

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