Here’s a challenge for you: See how many calories you and your partner can burn during your next sweat session. See who can burn more. Then see if you can beat those numbers each time thereafter. Oh, and we’re not talking about a sweat session in the gym. We’re talking about sex.

The team at SuperDrug Online Doctor created an exclusive interactive “sexercise” calculator for Men’s Fitness that’s as entertaining as it is informative. All you have to do is plug in some basic information about you and your partner (i.e. your sex and weight), your go-to sex position (or positions; you can add as many as you like), and how long you went at it to discover how many calories you burned.

To create these figures, they calculated a metabolic equivalent (MET) score for men and women in each sex position (they have 20 ranging in intensity from oral sex to holding your partner up.) A MET score shows how many calories you burn in an activity; so the equation looks something like this: Calories = (MET)(weight: kilograms)(time: minutes).

Once the calculator has calculated the calories you and your partner burned in each stage of intercourse, it gives you the option to see how many calories you could burn in equivalent exercise, and how much food you could burn off.

Say you went for 80 minutes. You and your partner can be expected to burn about 300 calories. This burns off five Oreos or two beers, and you could burn a similar amount of calories running three miles or doing yoga for an hour. Sure, running may be more efficient but what's more fun?