This calculator will tell you how much time you’ve wasted on Facebook

Well, this is disturbing… I have apparently donated more than a month of my life to Facebook. That’s according to TIME’s new web tool which calculates how much time you’ve spent scrolling through your Newsfeed and posting status updates on the world’s most popular social network site.

Released in the run up to Facebook’s tenth birthday, the calculator uses Facebook’s API to estimate how many days, hours and minutes you’ve spent using the service since you first joined. You simply allow it to access your Facebook account and it will go back in time, tallying up all your posts right back to the first one. Once it’s done processing, it will inform you not only of the time you’ve spent, but how much of Facebook’s own lifespan you were a member for.

The tool does have some limitations though — as its creators point out, Facebook doesn’t share data on how often a user logs in, so this isn’t an exact process. Instead, it asks you to estimate how much time you spend on the social network site (the average is 17 minutes a day) and works backwards from there. As TIME puts it:

This app runs through the timestamps on every post in your feed until it reaches the earliest one, which it uses as the estimated date that you created your profile. Users who are extraordinarily active on the site may get an estimate that is considerably later than the actual date that they joined.

Interestingly, TIME decided to style this tool as a calculator of the time you’ve wasted on Facebook. But not all that time spent uploading photos and liking shared memes was wasted, right? Right?