Enter all four sides to calculate trapezoid properties
Trapezoid Formulas
About Trapezoids
A trapezoid (or trapezium in British English) is a quadrilateral with exactly one pair of parallel sides. The parallel sides are called bases (a and b), and the non-parallel sides are called legs (c and d).
The height is the perpendicular distance between the two parallel sides. It is computed from the side lengths using the relationship between the legs, the difference in bases, and the Pythagorean theorem.
The midsegment (or median) connects the midpoints of the two legs and is always parallel to the bases. Its length is the average of the two bases: m = (a + b) / 2.
An isosceles trapezoid has equal-length legs, resulting in a symmetric shape with equal base angles. If both pairs of sides are parallel, the shape is a parallelogram.
The diagonals of a trapezoid can be calculated using the law of cosines applied to the triangles formed by the diagonals and the sides.
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are computed using standard formulas and should be verified for critical applications.
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Trapezoid Calculator FAQ
What is Trapezoid Calculator?
Trapezoid Calculator is a free geometry tool that helps you Calculate area, perimeter, height, and diagonals of a trapezoid.
How do I use Trapezoid Calculator?
Enter your input values, review the calculated output, and adjust inputs until you reach the result you need. The result updates in your browser.
Is Trapezoid Calculator private?
Yes. Calculations run locally in your browser. Inputs are not uploaded to a server by default, and refreshing the page clears session data.
Does Trapezoid Calculator require an account or installation?
No. You can use this tool directly in your browser without sign-up or software installation.
How accurate are results from Trapezoid Calculator?
This tool applies standard formulas or deterministic processing logic for estimates. For medical, legal, tax, or investment decisions, verify with a qualified professional.
Can I save or share outputs from Trapezoid Calculator?
You can bookmark this page and copy outputs manually. Results are not persisted in your account and are typically not embedded in the URL.