Updated

Giada always looks beautiful, Jamie Oliver has a rugged charm and Guy Fieri seems, well, not really ageless.

Do you know how old your favorite celebrity chefs are --or at least appear to be?

Microsoft has just invented a new website how_old.net that uses data imaging software to guess people’s age from one picture. Using algorithms based on 27 facial points, the software guesses your age and gender after you upload a pic. You can read more about how the scientists incorporated the data here, but the disclaimer admits there are still plenty of kinks to work out. “Sorry if we didn’t quite get the age and gender right – we are still improving this feature,” the site reads.

We tested the site with a few pictures of some of favorite celebrity chefs with surprising-- and sometimes hilarious -- results.

This chef looks much older than he really is. 

Guy Fieri

Real age: 47

Guess that spiky hair look isn’t the most youthful hairdo.

These celebs are shockingly youthful.

Paula Deen

Real age: 68

Giada De Laurentiis

Real age: 44

Rachael Ray

Real age: 46

Microsoft managed to get quite a few ages right.

Gordon Ramsay

Real Age: 48

David Chang

Real age: 37

Mario Batali

Real age: 54

We have a winner!

All original images via Associated Press. Screen shots created from how-old.net.