Some say beauty is in the eye of the beholder.

We beg to differ.

Which is why we found something based on hard science and mathematical logarithms that'll set the record straight once and for all—or at least be a fun party trick.

Let us present Vanity, the latest iPhone app that's going to change how you evaluate people—or more specifically rate the hotness of the redhead eyeing you from across the bar—available now.

The app doesn't need much more than a quick snapshot to work its magic, which is where a little charm and finesse will come into play. Tell her you're doing field research in the name of science (and if she's still on the fence, mention that it'll help the children).

Once you've got a straight-on head shot framing her face from forehead to chin, zoom in and center the blue vanity dots over features like her pupils, nose, mouth and chin (for what it's worth, makeup, hair and clothes don't count). After the dots are locked in place, the app will calculate a score on a scale up to ten. You can save the results and share them via Facebook, then make your move. Or pass.

And if you need to put everything in perspective, go to the Vanity Report website and compare your results to celebs like Angelina Jolie and Megan Fox (both 9.2) or Brad Pitt (8.3).

Finally, mathematical proof Brad's overrated.