This comic was pretty funny, and the age/2 + 7 formula got tossed around a lot by my roommates.

Of course, it gives us the minimum age one can date without being creepy. At 22, it’s [(22/2) + 7], or 18. (I, however, maintain that this discrepancy would, in fact, be creepy.)

But what about the upper age limit? The formula itself is silent on this, but we can easily do some substitution to make it work. If the minimum acceptable age (“M”) is your own age (“A”) divided by two, plus 7, we get:

M = A/2 + 7

We typically solve for M, knowing A. However, the oldest person I could date would have my A as their M, e.g.:

22 = A/2 + 7

With this realization, it’s a simple Algebra 1 question. Subtract 7 from both sides and then multiply by two.

Thus, the maximum age one can date is 2(a-7), where a is your age. For me, it’d be 2(22-7), or 30.

What interests me, though, is that this means I’m allowed to go back four years, but forward eight, within the margin of creepiness.

I built a spreadsheet for people aged 1 to 100 showing this and various other statistics. It’s online here as an HTML document. A few interesting trends emerge that aren’t intuitively obvious working with just the formulas:

• The formula doesn’t make any sense below age 14.
• Age 14 is a sort of ‘identity,’ when you’re first able to start non-creepily dating people, apparently, without breaking any laws of mathematics. At age 14, you can’t date anyone older, nor younger, than 14.
• From there on out, every year you age adds 0.5 to the minimum age you can date, while adding 2 to the maximum age. Thus at 22, I can date 18-30. When I turn 23, my new range will be 18.5 to 32. (At age 100, you can date anyone between 57 and 186. Because dating anyone over 186 would definitely be creepy.)
• As you can see, the two don’t grow at the same speed; the upper age grows four times as fast as the lower age. An interesting side-effect of this is that this means that, as time goes on, your age becomes radically different than the median age. By the time you reach 100, you’re 21.5 years younger than the median age of people you can date.