C Free’s carbon footprint calculator


How does C Free's carbon footprint calculator work and how was it built?


Aug. 21, 2020, 1:24 p.m. by Anna Prendergast

C Free is the UK’s first carbon footprint calculator to take a two-pronged approach to . First, we calculate your carbon footprint using our custom-built calculator. Then, we use that calculation to help you directly support a project of your choice in order to offset your CO2e emissions. And on top of all of that, we help you understand how you can reduce your carbon footprint in the first place so that ultimately, you have less to offset – and less to pay. 

So, how do we work it out? C Free’s numbers are based on peer-reviewed research, government data, and studies from internationally renowned academic institutions such as the University of Leeds and the University of Southampton. We tested our calculator against well-established numerical findings in the field and formulated a Base Rate by analysing consumption rates of public services (e.g. street lamps, the NHS, etc.) and aggregated consumption rates of carbon-producing activities (i.e. water consumption, and waste removal). 

In addition, we incorporated indirect emissions as well as direct emissions in our calculations (e.g. the difference between driving your car versus taking a taxi – you might not have filled the taxi up with fuel yourself, but you’re still responsible for the emissions produced on that journey). Whilst we believe that carbon should not be a moral issue, we also think it’s reasonable that as modern day consumers in the UK, we should be held accountable for emissions produced on our behalf – i.e. those created by other entities (e.g. that taxi) that responded to our demand.

“We know now more than ever that when it comes to the climate crisis, time is of the essence.”

We’re also committed to being transparent about the fact that data science is not exact, so optimising the user experience was of equal concern. “We came up with questions that cover as much ground as possible but that could also be answered by the consumer in the shortest time,” says Eddie. “We know now more than ever that when it comes to the climate crisis, time is of the essence.” To maintain its accuracy, the calculator is in constant review, too, being checked every six months and when new data sets are released. 

C Free has pooled this research and used it to simplify the process of calculating your carbon footprint. Our calculator was custom-built from the ground up by our founders, Eddie (who’s got an eye for design) and Adam (using his background in physics and data science). It was a labour of love, and took them just under a year to programme – and it focuses on the four main areas where consumers produce carbon emissions: living, eating, buying and travelling. It’s designed to streamline the act of calculating, so that it’s as accessible and user-friendly as possible, without cutting corners on the important stuff. Give C Free’s carbon calculator a go – it’s free, and because we want to raise awareness first and foremost, there’s no obligation to sign up.

Whilst the calculator is designed to be as quick and easy as possible, we also understand that there are enough forms to fill and boxes to tick in life – so if you’d rather simply skip this step and jump straight to offsetting, we have options available for that too, allowing you to offset for 75%, 100% or 125% of the average UK person’s carbon footprint. We’re also developing the option to offset a specific tonnage, flights, households, pets, and kids, so that if you want to ‘top up’ your contribution or make a one-off offset, you can do it within the safety of your C Free account. Had a dramatic change in lifestyle that means your carbon footprint has increased? Soon our online service will allow you to update your carbon footprint and automatically adjust your subscription.

Think we’ve done a good job? Reckon we’ve missed something in our calculator? Drop us an email to let us know – or just say hi.