In all the fun of soaking up the last bits of summer, it's easy to get carried away and lose track of what you're drinking and how it is actually affecting you. But with this handy calculator, you can figure out exactly what you're taking in with each drink — and how it'll affect you throughout the rest of that sunny BBQ. To use the tool, created by alcoholic.org, input your height, weight, and gender into the site. Then, you can input the kind of drinks you're having and how many of them you'll slurp down. Once you've given it the info, the calculator will tell you how your blood alcohol concentration (BAC) level will change over time. It'll also let you know how many calories you're drinking and how much running, yoga, or strength training you'll have to do to work it all off (if you're so inclined). You might be surprised how fun it is to play around with. For instance, if you have two cosmos in just a half hour, you might already be over the legal driving limit. But it takes, on average, three domestic beers to get to the same BAC. And that second Bloody Mary at brunch? It could push you over .10 BAC. Of course, this all depends on your other variables, too. BAC is an important thing to keep in mind, because it can predict both the social effects (like altered reasoning) and physical effects (like loss of balance) you might feel as a result of alcohol in your system. So this tool could be the secret to avoiding a hangover and some embarrassment.