http://www.nhlbisupport.com/bmi/ you can calculate your BMI here.
The models that were kicked out of fashion week in Madrid had BMI's less than 14! Which is crazy, yeah. 18 is totally normal. I'm thereabouts. I calculated the BMI's of the people I knew - and you guys are fat bastards, sorry to say! Uh you might want to pass on the crispy patas, chongs. Haha.