WorldCalcs

Trapezoid Calculator

Enter the two parallel sides and the height to get the area and the median (midsegment).

Reviewed by the WorldCalcs team · Methodology · Last reviewed: June 2026

Area

30

A = ((a + b) / 2) × h

Median (midsegment)

6

m = (a + b) / 2

What is a trapezoid calculator?

A trapezoid (called a trapezium in British English) is a four-sided shape with one pair of parallel sides. This calculator finds its area and its median — the line halfway between the two parallel sides — from the two parallel side lengths and the height between them.

How it's calculated

The area is the average of the two parallel sides multiplied by the height between them: area = ((a + b) / 2) × h, where a and b are the parallel sides and h is the perpendicular height. The median (or midsegment) is just that average: (a + b) / 2 — and it always equals the area divided by the height.

Example

A trapezoid with parallel sides of 8 and 4 and a height of 5: median = (8 + 4) / 2 = 6, and area = 6 × 5 = 30 square units. Notice the area is simply the median times the height.

All calculations happen in your browser. Nothing is sent, stored, or tracked.

Results are estimates and may contain errors — for general information only, not professional advice. Always verify before relying on them. Disclaimer

How to use

Enter positive values for the two parallel sides (a and b) and the perpendicular height (h) between them. The calculator returns the area and the median instantly.

Values are rounded to about 6 significant digits.

Frequently asked questions

How do I find the area of a trapezoid?+

Add the two parallel sides, divide by 2, and multiply by the height: ((a + b) / 2) × h.

What is the median of a trapezoid?+

The midsegment connecting the midpoints of the non-parallel sides. Its length is the average of the parallel sides, (a + b) / 2.

Which measurement is the height?+

The perpendicular distance between the two parallel sides — not the length of a slanted side.

What's the difference between a trapezoid and a parallelogram?+

A parallelogram has two pairs of parallel sides; a trapezoid has exactly one pair.

Can I get the perimeter from this?+

Not from these inputs alone — the perimeter needs the lengths of all four sides, including the two slanted legs.

Is a trapezoid the same as a trapezium?+

In US English a trapezoid has one pair of parallel sides; in British English that shape is called a trapezium. This tool uses the US meaning.

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