Trapezoid Area Calculator
Area and perimeter of a trapezoid.
Enter your values
Enter the parallel side a you are working with.
Enter the parallel side b you are working with.
Enter the height you are working with.
Enter the leg c you are working with.
Enter the leg d you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Area
- 32
- Median (midline)
- 8
- Perimeter
- 26
- Height
- 4
Working
- 1A = ((10 + 6) ÷ 2) × 4 = 32
Quick answer
A trapezoid's area is the average of the two parallel sides times the height.
A = ((a + b)/2) × h
At a glance
| What it does | Area and perimeter of a trapezoid. |
|---|---|
| Category | Math |
| Inputs needed | Parallel side a, Parallel side b, Height, Leg c, Leg d |
| Main output | Area |
| Formula | A = ((a + b)/2) × h |
| Cost | Free — no sign-up, no download |
How to use the Trapezoid Area Calculator
- 1Enter both parallel sides.
- 2Enter the perpendicular height between them.
- 3Add the legs for the perimeter.
Inputs explained
- Parallel side a
- Enter the parallel side a you are working with.
- Parallel side b
- Enter the parallel side b you are working with.
- Height
- Enter the height you are working with.
- Leg c
- Enter the leg c you are working with.
- Leg d
- Enter the leg d you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Parallel side a10
- Parallel side b6
- Height4
- Leg c5
- Leg d5
Results
- Area32
- Median (midline)8
- Perimeter26
- Height4
- A = ((10 + 6) ÷ 2) × 4 = 32
Frequently asked questions
What if it is a right trapezoid?
One leg equals the height — enter it in both fields accordingly.
Is a parallelogram a trapezoid?
Under the inclusive definition yes, since it has a pair of parallel sides.
What do I need to enter into the Trapezoid Area Calculator?
Just 5 values: parallel side a, parallel side b, height, leg c, leg d. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Trapezoid Area Calculator work out the answer?
A trapezoid's area is the average of the two parallel sides times the height. It applies the formula A = ((a + b)/2) × h and shows the working so you can check each step by hand.
Is the Trapezoid Area Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.