Demo

Change the price in the box below to see the estimated carbon footprint go up and down. This demo uses Amazon.com's estimated CO2 footprint per USD for calculations.

CO2 Footprint

3.41 pounds

Chrome Extension

Carbon Calculator is available in the Google Chrome Web Store here: Download Carbon Calculator for Google Chrome

Installation

Simply click the link above and then click the blue "Add to Chrome" button:

After this, you'll see an orange banner at the bottom of supported pages like this:

Privacy

Carbon Calculator does not collect any information as you browse, nor does it share any information with third parties. Carbon Calculator does need to ask for Chrome permissions so it can read the price from websites. The code is fully open-sourced here so that you can take a look for yourself: Carbon Calculator Source Code

How Is the Carbon Footprint Calculated?

Estimating the Carbon Intensity for a Particular Item

Certain retailers publish a Economic Input-Output Life Cycle Assessment (EIO LCA) that attempts to account for the carbon emissions incurred in creating an item. The assessment generally include estimates of the carbon intensity for the following activities:

  • Production of all inputs (from the raw materials to the final product)
  • Transportation for all inputs as well as delivery to the customer
  • Packaging for the final product
  • Electricity for running the retailer (from keeping the lights on at physical stores to the electricity used by servers to process the sale)

It should be noted, this is an estimate and cannot fully account for all emissions attributable to the production of an item. At this time the EIO LCA model is most widely used, but Carbon Calculator is open to adopting new methodologies. If you have a concern about accuracy, feel free to raise an issue on GitHub: GitHub Issues

Estimating the Carbon Intensity for a Retailer

After computing the estimate of emissions for all items sold, an aggregate metric can be computed for the retailer: the estimated carbon released per dollar of revenue. Some companies (e.g. Amazon) provide this directly while others do not go this far and Carbon Calculator uses SEC reports to calculate this figure.

Supported Retailers

Carbon Calculator currently supports the following retailers:

If you know of a retailer that isn't supported on the list above but is publishing carbon footprint metrics, create an issue here: GitHub Issues

About Us

Is Carbon Calculator a Charity?

Not yet—but we're working on that. In the meantime, Carbon Calculator commits to publicly releasing revenue metrics and using any profits to purchase carbon offsets. This means Carbon Calculator is a good way to automatically offset your online shopping.

How Does Carbon Calculator Make Money?

On certain websites the Carbon Calculator browser extension will modify the URL to include our affiliate link (which means we'll get a cut of the sale if you purchase the item you're looking at). This is transparent to the user, and it does not allow Carbon Calculator to collect any information on users. We never see your data; therefore, we can never sell it.