Window-to-wall ratio calculator

Glazing percentage per facade and overall.

  • Free, no sign-up
  • Runs in your browser
How it is calculated

WWR = glazed area ÷ gross external wall area × 100, per facade and overall.

Check locally: Energy codes set WWR limits and define how areas are measured. Check the one that applies.

Questions

What is a typical WWR?

Many energy codes cap WWR around 40%, but limits vary by climate and code.

Is anything I enter saved or sent?

No. The calculation runs in your browser. Nothing you type is sent anywhere. You can copy the result, print it or download it as a CSV.