Los Angeles, Reality TV personality Khloe Kardashian uses a sex calculator to count the number of calories burnt during the act. “I found this 'sex calculator' that tells you exactly how many calories are burned between the sheets based on your gender, weight, position, style ('slow,' 'frisky' or 'fast and furious,' haha) and time frame. (sic),” Khloe wrote on her official website, reports usmagazine.com. "I'm all about having fun with fitness and it's the best way to stay motivated to work out. I had my team put together a list of sex positions that burn the most calories, because what's more fun than getting down??? LOL,” she posted. The 31-year-old television personality is happy to be open about what she prefers in bed as she previously revealed that she keeps a rhinestone whip beside her bed.