Trapezoid area, median (midsegment), and perimeter from the two parallel sides, height, and legs.. Trapezoid Calculator is a free online tool from the ToolsRift Math Calculators collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
Enter the two parallel sides, the height and the legs and the calculator returns the area, median and perimeter.
Area = ½ × (a + b) × h, where a and b are the parallel sides and h is the height between them.
The median = (a + b)/2, the average of the two parallel sides, which equals the length of the midsegment.
Add all four sides: the two parallel sides plus the two legs.