Growth Charts & Percentiles: Z-Scores, LMS Method & BMI-for-Age
Percentiles and z-scores with NORM.S.DIST/NORM.S.INV, the LMS formula behind WHO and CDC growth charts, percentile curves, BMI-for-age, growth velocity, crossing percentile lines, interpolation by age and a cohort summary: 8 graded labs on synthetic children with illustrative tables. Not medical advice.
The first lesson is free — no account needed.
About this course
A growth charts and percentiles course that explains the math behind child growth charts on synthetic children in a spreadsheet, for nursing, medicine, nutrition and public health students and data analysts. You convert z-scores into percentiles and back with NORM.S.DIST and NORM.S.INV, calculate weight-for-age z-scores with the LMS formula z = ((X/M)^L − 1)/(L·S) including the L = 0 case, invert it to draw the 3rd, 50th and 97th percentile curves, turn BMI into a BMI-for-age z-score and weight-status category, measure height velocity in cm per year between visits, count crossed percentile lines with review flags, interpolate L, M and S between table ages and summarise a screening cohort's share below −2 SD. The LMS tables are illustrative, and the WHO and CDC growth references are cited for the method only. Educational only, not medical advice. The first lab is free.
Lessons
- Percentiles ↔ Z-Scores with NORM.S.DIST & NORM.S.INVFree
- The LMS Method: z = ((X/M)^L − 1) / (L·S) Pro
- Drawing the Curves: the Value at a Percentile from LMS Pro
- BMI and the BMI-for-Age Z-Score Pro
- Growth Velocity: Centimetres per Year between Visits Pro
- Crossing Percentile Lines: Band Index & Review Flags Pro
- Between the Rows: Interpolating L, M and S by Age Pro
- Cohort Summary: Share below −2 SD & the Z-Score Distribution (with a Chart) Pro