Just enter the bases and height of the trapezoid below and click Calculate Area. Use a period or comma as the decimal separator.
Trapezoid Area Calculator
Result:
How to use the calculator
- Enter the Larger Base (B) of the trapezoid.
- Enter the Smaller Base (b) of the trapezoid.
- Enter the Height (h) perpendicular to the bases.
- Select the unit of measurement.
- Click Calculate Area to see the result.
Trapezoid area formula
The area of a trapezoid is calculated as the average of the bases multiplied by the height:
A = ((B + b) × h) ÷ 2
Where B is the larger base, b is the smaller base and h is the perpendicular height. The formula applies to right, isosceles and scalene trapezoids.
Practical examples
| Larger Base (B) | Smaller Base (b) | Height (h) | Area |
|---|---|---|---|
| 10 m | 6 m | 4 m | 32 m² |
| 12 cm | 8 cm | 5 cm | 50 cm² |
| 15 m | 9 m | 6 m | 72 m² |
| 8 mm | 4 mm | 3 mm | 18 mm² |
| 7.5 m | 4.5 m | 3 m | 18 m² |
Frequently asked questions
What is the formula for the area of a trapezoid?
The area is A = ((B + b) × h) ÷ 2. Example: B = 10 m, b = 6 m, h = 4 m → A = (16 × 4) / 2 = 32 m².
What is the height of a trapezoid?
The height is the perpendicular distance between the two parallel bases. Do not confuse it with the oblique sides — the height is always perpendicular to the bases.
Does the formula work for all types of trapezoid?
Yes. The formula A = ((B + b) × h) / 2 is valid for right, isosceles and scalene trapezoids. What varies between types is the shape of the sides, not the area.
Can I use a comma instead of a decimal point?
Yes. This calculator accepts both a comma and a period as the decimal separator.
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