How the estimate works
The calculator measures the actual bytes transferred when the page loads, converts that to energy, and applies a grid carbon-intensity factor to estimate grams of CO₂ per visit. It also projects annual emissions at a typical traffic level.
Lighter pages are better for everyone
A lighter page emits less carbon, loads faster, and costs less to serve. The full report shows your page-weight breakdown by resource type so you can see exactly what to trim.
Frequently asked
- Is the carbon number exact?
- It's a modelled estimate based on transfer size and standard factors, useful for comparison and tracking improvement — not a certified measurement.
- How can I reduce my site's carbon?
- Optimize images, remove unused JavaScript, use efficient caching, and choose a green host — the report flags the biggest contributors.