Trapezoid Calculator
Solve a trapezoid's area, height, or either base from the other three values. Reports the median (midsegment) length, and — with leg lengths — the perimeter and isosceles/scalene classification, plus a labeled diagram.
Input
Leave any ONE of base a, base b, height, or area blank — it's solved from the other three.
Output
The trapezoid diagram will appear here once solved.
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/trapezoid-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"base1": "6",
"base2": "10",
"height": "4"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `trapezoid-calculator` tool (Trapezoid Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/trapezoid-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Trapezoid Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
Solve a trapezoid's area, height, or either parallel base from the other three values, plus its median (midsegment) length. Add the two leg (non-parallel side) lengths for the perimeter and an isosceles/scalene classification, and get a labeled diagram either way.
The formula
For a trapezoid with parallel bases a and b and height h (the perpendicular distance between them):
area = (a + b) / 2 × hThe median (or midsegment) — the segment connecting the midpoints of the two legs — always has length (a + b) / 2, which is also area / h.
Solve for any of the four
Leave any ONE of base a, base b, height, or area blank and the calculator solves for it from the other three:
- Missing area →
area = (a + b) / 2 × h - Missing height →
h = 2 × area / (a + b) - Missing base a →
a = 2 × area / h − b - Missing base b →
b = 2 × area / h − a
If all four are supplied, the calculator checks they're consistent and flags it if they aren't.
Perimeter and shape (optional)
Fill in leg 1 and leg 2 (the two non-parallel sides) and the calculator also reports:
- Perimeter —
a + b + leg 1 + leg 2 - Shape — isosceles (equal legs) or scalene
How to use it
- Enter any three of base a, base b, height, and area — the fourth is solved for you.
- Optionally add both leg lengths for the perimeter and shape classification.
- Read the labeled diagram and the full solution, or copy the SVG source.
All calculations run in your browser — nothing is uploaded.
What if my four values don't match up?
If you fill in all four of base a, base b, height, and area, the calculator verifies area = (a + b) / 2 × h and tells you what area those three dimensions actually give if it doesn't — leave one field blank instead to have it solved for you.