Methodology behind the carbon footprint calculator

There are different ways to calculate the carbon footprint of an individual. If you have tried out more than one calculator, you have probably noticed that the questions differ and so do the results. The quick answer to why this happens, is that it depends on which data the calculator is based off, and what assumptions are made. For the GoClimate calculator, we have explained the rationale between the choice of underlying data and the calculations that we base the tool on in the Methodology, which can be accessed HERE

If there is anything in the methodology that you find questionable, please reach out to us! Let us know if you disagree, have a better source of data for something, or how we could improve. The calculator will change over time because emission factors are updated regularly, which means that your result can change in the future. It could also change if we find better data or an even better way to calculate. These adjustments are however most likely minimal, and the biggest change is what you do yourself!

We calculate Food with general values from a UK study. Flights are calculated with our own API, and Car with emission factors provided by national sources (so that differs depending on where you are). Housing is using calculations based on national data on energy and electricity usage and national emission factors. Personal consumption, which is the clothes, furniture and other things you purchase, is based on a national average, weighted based on how much you purchase brand-new. To this we add a buffer for Public consumption which is infrastructure, hospitals, education etc.

Curious to know more about your carbon footprint? Read the other posts in this series:

Me and my carbon footprint
What is a “carbon footprint”?
The carbon footprint of a home
The carbon footprint of a diet
The carbon footprint of our traveling
The carbon footprint of long distance traveling
The carbon footprint of shopping
The carbon footprint of public consumption

Or go to to calculate your carbon footprint now!

40 Replies to “Methodology behind the carbon footprint calculator”

  1. It would be really good if there were questions about shopping or personal consumption habits to also show the impact of not buying lots of clothes or of shopping in zero waste and local shops vs supermarkets

    1. Agreed— they automatically said my carbon impact from shopping was 5.1 tonnes (the highest number of all my impacts) when I barely shop at all. That doesn’t seem like a super accurate estimate of my actual carbon footprint.

    2. I agree. I didn’t get any questions about my shopping behavior but it assumed that I emitted a certain amount of CO2 anyway.

    3. I agree. I buy almost 75% of my clothes and household goods from local thrift shops, and when I have to buy an item online, say from Amazon, I try to get the item used. Are these actions taken into account for my carbon footprint? I also buy handmade items from local artisians that do not produce asmuch waste as big companies.

  2. Since I focus the majority of my non-food shopping on second-hand items, I would like to see that calculated into my carbon emissions calculator.

  3. I was given 4.2 tonnes of emmissions for “public emissions and shopping” which needs more explanation, because i only take electrical trains, and i tend to buy very locally. The info lightly explained some addition for clothing and furniture, but i don’t really purchase those either. My consumption in France is very different from my consumption in Canada, and i expected to see more of a difference shown here. Thanks.

  4. As someone who is very conscious about my shopping consumption (I purchase my food from misfit markets, I thrift, purchase local & support small businesses, use earthhero, and try to purchase as little as possible; I do not appreciate being categorized with the national average of consumption. It would be really great to see more questions about personal consumption on this Carbon Calculator.

  5. Hi all! This is Stefan from the GoClimate team here.

    I just wanted to let you all know that we are hearing your feedback regarding options for shopping as a basis for our footprint calculator and we’re bringing it onto our agenda this week. I can’t give any promises on when you’ll see some changes, but we agree this category is important and are looking into how we could take it into account for the calculator.

    We want to make sure to be mindful of the fact that shopping contains so many different choices–all from clothing and everyday items up to and including car purchases and home renovations and anything in between–so it’s easy to miss asking for something you might do infrequently but that has a substantial impact on one’s overall shopping footprint. We’re looking for a good balance that is easy to give an overall answer to, yet doesn’t miss some huge little detail. What we’re aiming for is “roughly right” rather than “exactly wrong”. Depending on the amount and quality of data available, this might take longer or shorter to finish, but we are working on it!

    Thanks everyone for the feedback!

  6. No way this can be accurate. I don’t shop, which it automatically assumed you shop a great deal. I don’t heat my home at all, which wasn’t an option to choose. In addition, I drive a cng Powered vehicle, which again was also not an available option. I also live in a tiny home powered mainly by solar panels, so how can they guess your foot print by not knowing if your powering a large home or small or what your power source is, much less your vehicles fuel option? I love this idea but please fine tune this! I was ready to offset my foot print, and that of my two children, but not knowing What it may actually be…. I won’t be dishing out my family funds on something quite so vague.

    1. Hi Carrie! Thank you for your feedback. It seems like you live an extraordinarily climate friendly life, which is awesome! This calculator was developed to cater to the 80% of the population, and as I’m sure you are aware of, most people live their lives without making significant sacrifices for the climate. Hence a standard, 3 min calculator like ours will not be able to provide answers that accommodate everyone’s unique choices. What you do is great and we’d encourage you to either sign up for free so you get our content, or sign up and adjust the amount that you pay to accommodate for your family’s situation. Best regards!

    2. Hello! I understand the limitations of your calculator of course. I understand that this is a rough estimate not an exact percentage. That said based on what I have seen on the sight I am disappointed/wary about the lack of attention given to food. I controlled for all other answers in my quiz and found selecting “lots of meat” vs “plant based” only changed my monthly plan by 1 dollar. I know that to be impossible given the cold chain, shipping of food products, and other highly emissive process associated with meat eating. If you could point me toward a more elaborate break down of how this is calculated that would be great. If not, you absolutely should be considering using more of the research that is out there for that metric. Thank you so much!

      1. Hi Olivia!
        The values come from this study: – and it’s the most comprehensive study we’ve found which compares different diets. In this blog post: we explain more details about this data. Hope this gives a better understanding of the calculator results!

    3. Testet är dåligt.
      Vi som lever med naturen, är inte med.
      Ex. Ingen el, ingen bil, köper inga kläder.
      Handlar aldrig i affärer.

      1. Hej Stefan! Tack för din kommentar.Vi riktar oss till den stora massan, och har därför fokuserat på att göra ett enkelt test. Du verkar inte behöva ett test för att veta att du lever så klimatvänligt som det går, så grattis och tack för det!
        /Alexandra på GoClimate

  7. I understand your calculator is aimed at 80% of the population. At the same time, I am sure offering a choice of a more detailed calculator would be appreciated by many, since many off us coming her and compensating for our CO2 footprint are among the 20%. E.g. I installed 6,6 kW solar panels, I also consider investing in an electrical car. I share my hose with 4 other persons, and it is 190 square meters. I would love to calculate my CO2 footprint more precisely (why not a project with some local university to make sure values are validated when developing a optional more advanced calculator). Questions in the calculator will also hint what to do more for the environment and what effect it has on once CO2 footprint. Thanks!

  8. Here’s an update regarding to the shopping category of our calculator. We’ve now added a question to the test regarding shopping patterns, which is now accounted for in your result.

    The methodology in short is that we’ve looked at studies of total shopping and how much of that shopping is reasonably avoidable. Some types of purchases still remain such as leisure, rentals and repairs, which does have some carbon footprint. Picking the low-shopping option in the new version of the test now takes only those emissions into account for your result. More about the methodology in the updated link in the post above.

    We’re happy to answer any questions and hear your further feedback on this topic!

  9. When is it actually 2.5 tonnes CO2? When I fill in the most environmentally friendly options for each part of the survey, I still get more than 3 tonnes CO2. That means that nobody can reach the 2.5 tonnes according to your calculator, unless they are dead? Or am I missing something?

    1. Hi S! it’s correct that you currently cannot reach 2.5 tonnes with our calculator as it is today, and that’s because the public emissions are really high! If you look under the tab “More about your carbon footprint” you can see how the emissions are distributed, and see what you can influence today and what we collectively need to demand from politicians and companies. Dead people have the lowest carbon footprint, but they also don’t help us save the planet!

  10. Two elements, since it seems like my comment was deleted.
    1. Shouldn’t the focus be on reduction instead of offsetting? After everybody has done the calculator there should be key ‘biggest impact of improvement for reduction’ elements coming out. I understand offsetting is important, but reduction is even better
    2. There should be a way currently to reach the 2.5 tonnes CO2 in the survey, which there currently is none. That doesn’t paint an optimistic picture for the people trying to reach the 2030 goal that even if you don’t have a car, don’t travel, live on 15m2 and do everything right, you still don’t reach the 2.5 tonnes CO2, right?

    1. Hi Steph! The focus is, and will always be, on stopping climate change. We don’t need to choose between reduction and offsetting, we can do both. As you see on our blog and our social media presence, we focus a lot on providing support for how we can reduce our emissions. We agree with your suggestion, and it is on our to-do list to provide this feature!

      2. We agree, it doesn’t look good. The unfortunate truth is that it will not be enough with changing our personal lifestyles – we need to come together to make changes on a societal level. Vote for better politicians, argue for more sustainable banks, support NGO’s who do ground work, etc etc. It’s hard work, but the outcome if we stop climate change is gonna be amazing!

  11. It would be useful to have more questions about housing (e.g. what is the size of your home, and is it an apartment/duplex/townhouse/giant palace, whatever). I’d rather overpay than underpay of course, so for the purposes of this site it might be somewhat moot, but as a personal tool it is nice to know the impact of different types of housing.

    1. Hi Eileen, thank you for your comment! We try to keep the test as simple as possible, so we decided to slim this question as much as possible. There are more precise calculators that you can do if you are interested, I have tried a lot for myself and it’s very interesting to see!

  12. Hi, there!

    I think I have been part of this since 2018 and I enjoy getting updates on the projects. I took the test again in 2021, and like many others, I again got disappointed by the cookie-cutter approach: particularly assuming what food I eat. While I get the intended purpose behind it – and, that we can hardly do anything about this disaster without profound change from big-corp and governments – I think the test does more harm than good: It gives me the intuitive notion that you are trying to paint people in a poor light, to pressure them into joining. The guilty conscious of people can easily backfire and lead instead to freeze and inaction.

    The test is the very first item to be interacted with, the first product, or valuable information, that you present to your subscribers: I expected a measuring tool for myself and some kind of comparison that I could use together with others, to further help spread awareness. Instead, I found the whole test discouraging and sloppy. I did take the time to read up on your structure and operation, which is ambitious and why I decided to become a subscriber. I think the test could be much improved by a marketing professional.

    I really like what you are doing, my wife and I are supporting in the ways we can! Happy new year!

  13. Would love an option in the housing section to add how many people live in the house so that carbon footprint can be divided by that number.

  14. We produce energy with solarpanels during summer but there is no question about that. We produce about 10000 kWh a year, not much but its half of what we use a year. We live in Sweden so half of the year we need to heat ouer home some way. So as you see, my carbon footprint calculation show a very missleading number. So don’t forget us micro producers that give back solar energy during summer time.

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