If you've ever wondered just how many minutes, hours and days have been stolen from your life by Facebook, it's time to face the nonthreatening, pale blue truth head-on. Now, a tool developed by TIME's tech side lets you do just that by calculating precisely how long you've spent on the site since joining up, and the results can be sobering.

The bottom line depends on how long ago you joined the site and how active you are on it. Although data on exactly how often a user logs in isn't available, the calculator runs through the timestamps on every post in your feed until it reaches the earliest timestamp, then estimates from there (if you spend less than the average 17 minutes per day on the site, you can adjust this in the calculator, but ready to take a good hard look at yourself).

According to the calculator and using the default 17-minutes per day average spent on the site, this sheepish writer has wasted over 39 days on the site since joining up when the site was still open only to college students (a terrifying 10 years ago). Bonus fact: you can find out just where you fall on the continuum of Facebook adopters using this handy tool (if you went to Harvard, you'll likely be one of the earliest sheep to the slaughter).

Every Facebook users knows the dark allure of combing through our friends' photos, stalking exes and humble-bragging about our exaggeratedly wonderful lives, and we can't judge you for it. But every now and then it's good to pause and wonder just what that billionth generic baby photo is adding to our lives, and to act accordingly.

[TIME]