Growth Chart Calculator

The CDC growth charts data files

CDC growth chart data files is the source to produce the well known 2000 CDC Growth Chart for United States. These files contain the L, M, and S parameters needed to generate exact percentiles and z-scores along with the percentile values. The LMS parameters are the median (M), the generalized coefficient of variation (S), and the power in the Box-Cox transformation (L). To calculate the value (X) of a given physical measurement at a particular z-score or percentile, use the following equation: \[ X = M(1+LSZ)^{\frac{1}{L}}\ if\ \ L \neq 0 \] \[ X = M e^{SZ}\ if \ \ L = 0 \] For a given mreasurement(X), we can use the following formula to calcualte the z-score(Z) and then we can use the standard normal distribution function to find the percentile from the z-score: \[Z = \frac{(\frac{X}{M})^L - 1}{LS} \ if \ L \neq 0 \] \[Z = \frac{ln(\frac{X}{M})}{S} \ \ if L = 0 \]