The U.S. Centers for Disease Control and Prevention plots measurements of children according to percentiles, or how they compare to other children of the same gender and age. Although one child is in a top percentile and another is at the bottom, both children can be perfectly healthy and growing just as they should.

While you might be more familiar with other health-related ratios -- like weight-to-height ratios or waist-to-hip ratios -- the foot-to-height ratio can be helpful in some situations.

To determine whether a child is growing at a healthy pace in both height and weight, many pediatricians and child care providers consult widely available growth charts for comparison with other children. These charts reveal a range of normal heights and weights for both boys and girls.