Math

Trapezoid Area Calculator

Enter the two parallel sides and the height to find the area of a trapezoid.

By TheCalcTools Updated Formula checked and tested

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Area
Area
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Midsegment length
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Trapezoid Area Calculator by TheCalcTools

How the Trapezoid Area Calculator works

Enter the lengths of the two parallel sides and the perpendicular height between them.

The area is the average of the bases times the height.

The formula

A = (a + b) ÷ 2 × h

Worked example

Using the default values shown in the calculator:

Base a8
Base b5
Height4
  1. Average of the bases = (8 + 5) ÷ 2 = 6.50.
  2. Area = 6.50 × 4 = 26.00.

Result:

Area26.00
Midsegment length6.50

Frequently asked questions

Which sides are the bases?

The two parallel sides. The height is the perpendicular distance between them, not the length of a slanted side.

What is the midsegment?

The line joining the midpoints of the slanted sides. Its length is the average of the bases.

Sources and further reading

Rectangle CalculatorEnter the length and width to find the area, perimeter and diagonal Triangle Area Calculator (Heron's Formula)Enter three side lengths to find the triangle's area, perimeter and angles Triangle Calculator (Solve Any Triangle: SSS, SAS, ASA)Choose what you know and enter the values Circle CalculatorEnter the radius to get the diameter, circumference and area of a circle Pythagorean Theorem CalculatorSolve for any side of a right triangle using a² + b² = c² Sphere Volume and Surface Area CalculatorEnter the radius to find the volume and surface area of a sphere

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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.