What is the BMI chart and how does it work ?

KittyKat1106

Can someone post a BMI chart here and break it down for me how it works? I am not the type of girl who pays attention in a Dr's office. I am 155 last time I weighed myself roughly a month ago and as of yesterday the scale at my work (a nursing home, so Id HOPE we would have an accurate scale lol) read 146. I am buying a new scale tomorrow just to double check if that is infact my accurate weight. But I am 5"7 1/4 inches tall and was just wondering if 146 is overweight or just right for my height (I already know 155 is overweight). Just wondering !