You may have wondered about the "sex numbers" of your individual sex partners — but have you extended that question to their sex partners? To mark the U.K. Family Planning Association's annual Sexual Health Week, Lloyd's Pharmacy created a calculator that estimates how many sex partners your sex partners have had, up to six degrees of separation. You may find your number shockingly high (uh, I've had millions of sex partners?), but the quantity of direct/indirect sex partners you've had isn't what should concern you most. Instead, the tool is intended to highlight the importance of safe-sex practices and regular STI testing. "This calculator is not a diagnostic tool, but it highlights how exposed you can be to STIs and how this risk increases with each new partner," the website reads. "It's not just your direct partners that you have to worry about, but your partners' partners, their partners' partners, and so on." As Mic writes, Lloyd's Pharmacy released a similar test in 2013 to draw attention to increasing STI rates in the U.K. In the U.S., meanwhile, over 50% of people will contract an STI in their lifetimes. 19.7 million new STI cases occur a year; some estimates indicate that 40% of men and 50% of women could have genital herpes by 2025. So go ahead and calculate your number of sex partners to the sixth degree, but remember that the combo of safe sex and testing is what matters most.