You can’t manage what you can’t measure: A carbon calculator for websites

Jerome Toole

Jerome Toole

In 2016, the Wholegrain Digital team woke up to the fact that the internet is a huge contributor to climate change. In line with their mission to help create a sustainable future, they set about trying to figure out how to reduce to impact of the websites produced for clients. The renowned management consultant Peter Drucker said that “You can’t manage what you can’t measure”. With this in mind, the team set about reviewing existing research into web emissions and energy consumption to understand how it could be used to estimate website emissions and benchmark websites.

This gradually evolved into an internal tool used for agency projects and in 2018 was released at as a free tool for anyone to use. This talk will discuss why it is essential that web designers have a way to estimate the environmental impact of their work, the assumptions made to create a practical tool, and how this tool has impacted the work of the team in lowering the emissions of the websites that they create and maintain.


Jerome is a climate concerned web developer. Since his first web projects, he’s been focused on finding out how the web can be a tool for good. In 2013 he co-founded CauseHub, a social enterprise focused on finding out how to drive effective activism online. He is also co-founder of the BrainChild festival, held annually in the UK celebrating the DIY spirit, art, music and ideas of the people around us. He now works at Wholegrain Digital exploring ways to make the web more sustainable and also more delightful.