Website Carbon Calculator
How much CO₂ does your site emit?
Paste any URL and get an instant A+ to F carbon rating, based on page weight, hosting energy source, and real-world emissions factors.
URL to carbon rating in seconds
We analyze your page, measure every byte, check the hosting, and apply Sustainable Web Design Model v4. Learn more
Don't just measure — take action
Track each tangible impact in real-time. Live planting sessions, unmatched transparency.
Why does website carbon matter?
The internet produces approximately 3.7% of global carbon emissions — comparable to the entire airline industry. Every website visit requires energy: data centers process your request, networks transmit the data, and your device renders the page.
A typical web page emits around 0.36 grams of CO₂ per view. That may sound small, but multiply it by billions of daily page views worldwide and the impact becomes significant.
By measuring your website's carbon footprint, you can identify opportunities to reduce emissions through optimization — smaller page sizes, efficient code, green hosting, and optimized images all make a difference.
Our methodology
We use V4 of the Sustainable Web Design Model (SWDM), the industry-standard open methodology for estimating digital carbon emissions. The model calculates energy consumption across four segments: data centers, transmission networks, user devices, and embodied (manufacturing) emissions.
The total energy intensity is 0.30 kWh per GB of data transferred. Combined with the global average grid carbon intensity of 494 gCO₂e/kWh, this gives us the CO₂ emissions per page view.
Want to build with our API?
Integrate website carbon analysis into your own tools, dashboards, or sustainability platforms.
View API Documentation