Free to use, no account
Trapezoid Calculator
Enter both parallel bases, the perpendicular height and where the top base starts to calculate area, side lengths and perimeter.
How do you calculate the area of a trapezoid?
Add the two parallel base lengths, divide by two, then multiply by the perpendicular height. The top-base offset does not change area, but it determines the two side lengths and perimeter. All dimensions must use the same unit.
Frequently asked questions
How do you calculate the area of a trapezoid?
Add the two parallel base lengths, divide by two, then multiply by the perpendicular height. The top-base offset does not change area, but it determines the two side lengths and perimeter. All dimensions must use the same unit.
Are my measurements uploaded?
No. The calculation runs in this browser. Your measurements are not uploaded or saved.
What is the trapezoid area formula?
Area = (base A + base B) ÷ 2 × perpendicular height. The two bases must be parallel.
Does the top-base offset change the area?
No. With the same two parallel base lengths and perpendicular height, area stays the same. The offset changes the side lengths and perimeter.
Can I mix feet and inches?
No. Convert measurements first and enter all lengths in one selected unit so the area unit is unambiguous.