Carbon Calculator
Website Carbon Calculator estimates a website’s carbon footprint using the Sustainable Web Design Model.
About Carbon Calculator
Website Carbon Calculator is a free web-based tool created by London-based sustainable WordPress agency Wholegrain Digital, designed to estimate the carbon footprint of individual web pages. It uses version 4 of the Sustainable Web Design Model to calculate estimated CO2 equivalent emissions per page view, and compares results to the global average of 0.36g CO2 per pageview to give context for a site's environmental impact.
The tool is intended to raise awareness of the internet's significant energy use, which the site notes exceeds the total annual electricity consumption of the United Kingdom and produces emissions on par with the global aviation industry. It also provides resources on sustainable web design and showcases examples of low-carbon websites that have been tested with the calculator, making it a useful reference for anyone looking to reduce the environmental impact of their online presence.
Key features
- Estimates webpage carbon footprint using Sustainable Web Design Model v4
- Compares site emissions to the global average per pageview
- Showcases tested low-carbon websites with their CO2 output metrics
- Provides resources for designing sustainable, low-carbon websites
- Offers digital sustainability consulting from the creator agency
Best for: Web developers, site owners, and sustainability professionals seeking to measure and reduce their website's carbon footprint.
Good for
- Free to use with no sign-up or payment required
- Uses a purpose-built, recognized methodology for web carbon estimation
- Hosted on renewable energy, aligning with its sustainability mission
- Includes real examples of low-carbon sites for reference
Watch out for
- Provides only high-level carbon estimates, no granular emission source breakdowns
- Does not include built-in tools to directly reduce website emissions
Carbon Calculator at a glance
- Website
- websitecarbon.com
- Category
- Development › Developer Tools
- Type
- Online tool
- Pricing
- Free
- Platforms
- Web
- Open source
- Not stated
- Language
- English
- Last checked
- Oct 5, 2026 · Online when checked
- Listed
- Oct 5, 2026
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Carbon Calculator FAQ
How does the Website Carbon Calculator estimate emissions?
It uses version 4 of the Sustainable Web Design Model to calculate estimated CO2 equivalent per webpage page view.
Is the Website Carbon Calculator free to use?
Yes, the tool is completely free with no sign-up or payment required.
What is the average carbon footprint of a web page?
The global average is approximately 0.36 grams of CO2 equivalent per page view.
Can I get support reducing my website's carbon emissions?
The creator agency Wholegrain Digital offers digital sustainability consulting services for web projects.
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