Trapezoid Calculator

A trapezoid (called a trapezium in British English) has one pair of parallel sides.

Trapezoid

Area32
Median (midsegment)
8

Working

  1. A = (a + b) ÷ 2 × h = (6 + 10) ÷ 2 × 4 = 32

Enter both leg lengths to also get the perimeter.

Formulas

area = (a + b) ÷ 2 × h

midline = (a + b) ÷ 2

perimeter = a + b + c + d

Worked example

Parallel sides 6 and 10, height 4

  1. Average of parallel sides: (6 + 10) ÷ 2 = 8
  2. Multiply by the height: 8 × 4 = 32

The area is 32 square units.

Where trapezoids appear

Cross-sections of ditches and embankments, roof faces, some garden beds and table tops. The area formula is also the basis of the trapezoidal rule for estimating the area under a curve.