Trapezoid Calculator
Enter both parallel sides and the height below to instantly get the area, plus the perimeter if you add the two legs.
Optional — add both legs to also get the perimeter:
Area
55
Perimeter
34
Trapezoid Formulas
Area = ((a + b) / 2) × h. Perimeter = a + b + c + d, where c and d are the two legs.
Worked example
A trapezoid with parallel sides 8 and 14, and height 5.
Area = ((8 + 14) / 2) × 5 = 11 × 5 = 55
Frequently Asked Questions
What is the formula for the area of a trapezoid?
Area = ((a + b) / 2) × h, where a and b are the two parallel sides and h is the perpendicular height between them.
What is the formula for the perimeter of a trapezoid?
Perimeter = a + b + c + d — simply add up all four sides, including the two non-parallel legs.
What's the difference between a trapezoid and a parallelogram?
A trapezoid has exactly one pair of parallel sides. A parallelogram has two pairs of parallel sides (both pairs), which is a stricter condition.
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