Trapezoid Calculator
Area of a trapezoid from its two parallel sides and height.
Worth Knowing
A trapezoid's area is the average of its two parallel sides multiplied by the height, an intuitive formula once you picture it as a rectangle whose width is the midpoint average. This 'average the parallel sides' idea generalizes usefully — it's the basis of the trapezoidal rule for estimating the area under a curve in calculus. Only the perpendicular distance between the parallel sides counts as the height, not the length of the slanted sides.
How to Use
- Enter Base a into the first field of the Trapezoid Calculator.
- Fill in the rest: Base b, Height.
- Your result appears instantly as you type — there's no submit button or page reload.