Area of Trapezoid Calculator

Calculate trapezoid area instantly. Free online trapezoid area calculator with parallel sides and height.

The Area of Trapezoid Calculator finds the area of any trapezoid using the two parallel sides (bases) and the height. Trapezoids appear frequently in architecture, construction, and design. This tool applies the formula A = ½(b₁ + b₂)h to give you accurate area calculations for trapezoidal shapes in your projects.

Common use cases

  • Roof section calculations
  • Land parcel measurements
  • Channel cross-section areas
  • Architectural features
  • Table and furniture design

How to use

  1. Enter the first parallel side (base 1)
  2. Enter the second parallel side (base 2)
  3. Enter the height (perpendicular distance)
  4. Click calculate for the area
  5. View the formula application

FAQ

What is the trapezoid area formula?

Area = ½ × (base₁ + base₂) × height, where bases are parallel sides and height is perpendicular distance.

Which sides are the bases?

The two parallel sides. They don't have to be horizontal—just parallel to each other.

How do I find the height?

Height is the perpendicular distance between the parallel sides, not the slant height.

What about irregular quadrilaterals?

This formula only works for trapezoids (one pair of parallel sides). Other quadrilaterals need different methods.