Trapezoid Area Calculator
Calculate the area of a trapezoid from its two bases and height — get the result instantly.
Formula
S = ½ · (a + b) · h
where a and b are the parallel bases and h is the height
About the Trapezoid Area Calculator
A trapezoid is a four-sided shape with two parallel sides. Those parallel sides are called the bases, and the perpendicular distance between them is the height.
To find the area of a trapezoid, add the two bases, multiply by the height, and divide by two. This is useful in geometry, construction, fabrication, and land area estimates.
All calculations run instantly and locally in your browser — nothing is uploaded, keeping your numbers completely private.
Benefits
Instant result
The area updates as soon as you enter the bases and height.
Simple input
Just three values are needed: the two bases and the trapezoid's height.
Fully private
The calculation happens locally in your browser; your numbers never leave your device.
Frequently Asked Questions
How do you calculate the area of a trapezoid?
Add both bases, multiply by the height, and divide by two: S = ½·(a+b)·h. For example, with a=4, b=6 and h=5 the area is 25.
What is the formula for the area of a trapezoid?
The trapezoid area formula is S = ½·(a+b)·h, where a and b are the lengths of the parallel bases and h is the height between them.
What are the bases of a trapezoid?
The bases are the two parallel sides of a trapezoid, labeled a and b in the formula. The slanted sides are not used to find the area.
What counts as the height of a trapezoid?
The height is the perpendicular distance between the two parallel bases, not the length of a slanted side.
What units does the area come out in?
Area is measured in square units. If you entered the bases and height in centimeters, the result is in square centimeters (cm²).