# Trapezoid Area Calculator

> Trapezoid area calculator: area from bases and height. Free trapezoid area calculator with the formula shown - runs entirely in your browser, no signup.

- **Canonical URL:** https://boringtoolskit.com/trapezoid-area-calculator/
- **Category:** Everyday Calculators
- **Evidence level:** authored-methodology
- **Reviewed:** July 26, 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

## How it works

Area = (base1 + base2) / 2 x height.

## Worked example

A trapezoid with bases of 8 and 12 and a height of 5 has an area of 50 square units.

## Assumptions

- The two bases are parallel.
- Height is the perpendicular distance between the bases.

## Common questions

### What if I only know the legs, not the height?

Use the Pythagorean theorem on the leg and the base offset to find the perpendicular height first.

### Do the bases have to be parallel?

Yes. Without a parallel pair the shape is a general quadrilateral, not a trapezoid.

## Related tools

- /area-calculator/
- /triangle-area-calculator/
- /circle-area-calculator/

## Sources

- [Calculation methodology](/methodology/)
- [Quality evidence and verification standard](/quality-evidence/)

---

*Local planning estimate. Verify current terms, rates, and policies before acting.*