How we calculate your website’s CO2 emission

We take your servers, your data traffic and your visitors’ consumption into account, and then we add a buffer.

How much power does a webserver consume?

We assume a webserver is running 24/7/365. The effect of a small server typically amounts to 200 Watt, but it’s now normal to use large hosting solutions which means bigger servers but more sites on the same server. This results in a smaller power consumption per website. Nevertheless, we have chosen to calculate 200 Watt which gives us a comfortable buffer.

How much power does a website visitor consume?

Our starting point is a standard laptop with a 17” screen. It consumes 173 Watt. To this we add the consumption of the router and thus arrive at 200 Watt per user. However, pageviews are more important for your visitors’ power consumption.

On how many pageviews do we base our calculations?

We base our calculations on the number of monthly pageviews reported by our members. Pageview numbers are not publicly available information, so we trust our members. To be on the safe side, we ask you to report your pageviews as a traffic interval. This ensures that we always estimate your traffic higher than it actually is.

How much power does a pageview consume?

Our variable for time-on-page comes from Nielsen Online who calculates monthly statistics in this field. Their average time-on-page is calculated to ca. 50 seconds. We set our baseline to 60 seconds which gives us a 20% buffer. We don’t ask you to reveal how much time your visitors spend on your site. That can be considered a trade secret. However, we use the advantage of having a lot of members. Some have more traffic than expected, others have less.

How much power do the cables between servers and data centers consume?

We estimate the power consumption of the data cables that connect servers and users to be 1 Watt/month per pageview. As a baseline, we set every month to 31 days which actually gives us a 2% buffer because some months have 28 or 30 days. For websites that have extreme traffic numbers, we can make more specific calculations.