Trapezoid Area Calculator
Find a trapezoid's area, median and perimeter in one step — enter the two parallel sides and the height for area, or add the two legs to get the perimeter. Formulas are shown so you can follow the working.
Enter values — the result shows live here.
How to use
- Enter the parallel sides a and b and the height.
- Also enter legs c and d to get the perimeter.
- The median (average of the two parallel sides) also shows in the result.
Note: Formula: Area = ((a + b) / 2) x height. Median = (a + b) / 2, and Area can also be written as median x height. Perimeter is the sum of all four sides.
Good to know
- Area = ((a + b) / 2) × height — the median times the height gives the same result.
- Sides a and b must be the parallel pair; the legs c and d are only needed for the perimeter.
- All four sides must use the same unit, or the answer will be wrong.