First off, let me say  first and foremost that we at HackCollege do not condone underage drinking. We do, however, know a few things to be true when it comes to college students and booze: you will at some point pass out in the most embarrassing way possible, you will vomit on a clothing item you particularly like, and you will almost certainly get to both of those points with the help of alcohol hidden away in plastic water bottles.

Drinking hard alcohol out of a re-used water battle is a tried-and-true staple of college drinking; whether you’re at anything from a frat party to a football game, you can be sure that at least a couple of your peers are getting wasted on vodka served out of a Dasani bottle. It’s also a great way of getting entirely too drunk, as you can never be sure exactly how many shots you ended up pouring in there.

Now, a new iPhone app dubbed Shots iGot is here to help change that to let you know exactly how much alcohol is in 44 different containers used as surreptitious flasks, such as Coke bottles, red Solo cups, and pop cans. Using the volume of all these containers, the app shows you just how many 1.5 ounce shots are present  in a visual representation.

All you have to do is look at how much booze you’ve poured into your bottle, adjust it to the approximate amount on the app, and then gives you an estimation of how many shots that level of alcohol amounts to, and is accurate to 1/10th of a shot. Afterwards, the bottle is saved in the apps library, so you can find out the day  after just how much you managed to drink. You can even take a picture of your water bottle with your phone and import it into the app in order to match the exact level of liquid.

The app also has a “mixer mode,” which will let you know how much alcohol is present if you mix it with an amount of other liquids in the same fashion; input the amount of mixer you have in the bottle, and the app will tell you how much alcohol would be present if filled all the way up.

One of the apps creators, Paras Jain, said that the inspiration behind the app came from seeing fellow students at parties constantly drinking from plastic bottles without ever knowing just how much they were imbibing.

“My buddy Josh [Rosenheck, now CEO of their startup] and I, we both were at our fraternity at Rutgers, and we used to see girls and guys carrying out bottles around all the time,” he said. “And the girls would say, ‘How many shots do you think I have in here?’ One day my buddy Josh … said to me, ‘Wow, now there’s an iPhone app — that you can just virtually see the number of shots,’ and it just clicked.”

The app is available in a free version, which features a limited number of containers, and a paid version with all 44 containers for $1.99.