Fundal Height-Belly Size

I just read online , actually in one of the blog that the distance from the top of the uterus to the pubic bone measured in centimeters. It should match the number of weeks you are in pregnacy (24 weeks = 24 centimeters). 

On 13th Feb , During 22 weeks 6 days, When I went to the doc, she measured my belly and said loos good. I didnt know whats the logic behind it, ofcorse I know its to measure the belly but the fact is as above. So its good I knew about this. Later if I want to measure by selves I can do it just for fun :). I know the Doc does this everytime when I go and meet her.