Trapezoid Calculator
Calculate the area, median, and perimeter of a trapezoid from its two parallel sides, height, and (optional) leg lengths.
Trapezoid dimensions
Area
28
- Median
- 7
- Perimeter
- 24
Frequently Asked Questions about the Trapezoid Calculator
What is a trapezoid?
A trapezoid (called a trapezium in British English) is a quadrilateral with exactly one pair of parallel sides. The two parallel sides are called bases (a and b), and the perpendicular distance between them is the height (h).
How do you find the area of a trapezoid?
Area equals one-half times the sum of the two parallel sides times the height: A = (a + b) / 2 * h. The calculator does this and shows the result in your chosen units.
What is the median of a trapezoid?
The median is the line segment that connects the midpoints of the two non-parallel sides. Its length equals the average of the two parallel sides: (a + b) / 2. The area also equals median times height.
Why does perimeter require all four sides?
Perimeter sums every side. The two parallel sides and the height alone do not determine the lengths of the non-parallel legs (c and d) unless the trapezoid is isosceles. Enter c and d to get perimeter.
Does the trapezoid have to be isosceles?
No. The area formula works for any trapezoid (isosceles, right, or scalene). All it needs is the two parallel sides and the height. Perimeter still requires the actual leg lengths.