# Window Size Calculator

> Window size calculator: compute rough opening, glass area, and standard window sizes from your wall framing dimensions. Free, private, in your browser.

- **Canonical URL:** https://boringtoolskit.com/window-size-calculator/
- **Category:** Construction & Measurement
- **Evidence level:** catalogue
- **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.

---

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