Welcome to the International Student Carbon Footprint Challenge!
calculate your footprint



Before thinking about efficient ways to reduce our impact on the planet, we need to know exactly how much our different behaviors impact our carbon footprint.

Our International Student Footprint Calculator will allow you to do just that! The questionnaire is divided into four parts: transportation, home energy and appliances, food and personal purchases.

Answer the questions as honestly as possible and keep an eye on your amount of CO2 release per year at the bottom of the screen as you continue. You may be alarmed at times by the results!


We offer (and strongly suggest that you use) the ability to register at the site, so that your data will be automatically saved as you progress. That way you can complete the calculator questionnaire in more than one sitting, and return anytime to explore all of the features of the calculator and to update your footprint calculation based on lifestyle changes.

*Note that the new version (May 2015) of the calculator will currently not allow you to register during your calculation, so we strongly suggest that (for now at least) all students register before starting their calculations!

*Update May 20, 2015: We know of at least one problem that some users are encountering: a "NaN" error in one or more sections in place of the footprint value. Navigating back and then forward through the questions in the problematic section should fix this error, which we believe is caused by accidentally skipping questions.

*If you should encounter that or any other problem with the new calculator, please email Jason Hodin at seastar(at)stanford.edu and he will try to help.

Once you start the questions, keep in mind that it can take 25-30 minutes or more for English-proficient students to complete them (50 minutes for those for whom English is a second language [ESL]).

We suggest that students fill out this Calculator Prep Worksheet in advance, it will make the online calculation faster and more accurate.

*May 12, 2015: Prep worksheet now updated with new calculator options (e.g., LED lights)!

*You may wish to download our class assignment to reflect on what you discover as you use the calculator (not yet updated for the new May 2015 calculator).

*You may also wish to download this pictorial key (updated May 2015) to the features of our calculator (or this one for our mobile/tablet version).

For the new calculator version (May 2015), we do not yet have a dedicated source document posted - but all sources are available on demand during the calculations when you press the documentation button, which looks like this:

As of March 2013, a German language version of the calculator is available! (Flash only - no mobile version yet)

If you have problems with the new calculator version (May 2015), and/or you would prefer the older Flash version, we are archiving it at this link.

When you are ready to start your footprint calculation, click the button below...