Bulk Z-scores and percentiles
Z-score and percentile calculations for a whole data file: from one selected chart, for many children, with one row per date for multiple measures. The results are those of the chart's calculator for the same values.
1 Chart
2 Your data file
🔒 Your file stays on your computer: only sex, ages and measurements are sent. More…
Open a file
or drop it here
CSV, Excel (.xlsx, .xls) or OpenDocument (.ods); the first row names the columns; up to 10,000 rows.
Paste from a spreadsheet
3 Columns
Check which column of your file is which, and its units. Columns you leave out stay in the results unchanged.
4 Calculate
What will be sent to PediTools
5 Results
Advanced download options
For statistics software (e.g. R, Stata, Python): column names without spaces, and a long layout.
Help
Choose the chart, open your data file, check its columns and calculate: the results appear below, to download as Excel or CSV. Nothing identifying leaves your computer.
Preparing the file
- One row per measurement, with a header row naming the columns. Other columns (e.g. an ID) are kept as they are.
- Sex: M or F (or male, female). Number codes such as 1 and 2 are not read.
- Age, one of two ways (step 3 asks which): the chart's age in a column (the PMA for preterm charts), or the date of birth and the date of measurement, with the year (preterm charts: with the GA at birth). Other ages, e.g. from a due date, are worked out before. Size-at-birth charts take the GA at birth.
- Corrected age: on charts that offer it, an optional GA at birth column adds results for the corrected age.
- PMA and GA at birth: weeks and days, e.g. 30 3/7 or 30+3, or decimal weeks, e.g. 30.43 (rounded to whole days).
- Measurements: in the unit named in the column's header, e.g. Weight (kg). A cell with its own unit is read as typed, e.g. 8-4 for 8 lb 4 oz, or 19" for inches.
- The chart's CSV template and example file show the columns.
What is sent
Your file is read by this page in your browser and is never uploaded. To calculate, the page sends PediTools only the columns the growth chart needs: sex, the age or gestational age, and the measurements, as they appear in your file. Dates of birth and of measurement are turned into ages in days in your browser; the dates themselves are not sent. Names, record numbers, notes and every column you do not choose stay in your browser. "What will be sent to PediTools" shows exactly what will be sent before you calculate.
PediTools calculates and returns the results; nothing is stored or logged. The results and the downloads are made in your browser.
The results
- Every row of your file, then the age used, and for each measurement its Z-score and percentile. Also, where they apply: the value used when a measurement was entered in another unit, BMI, the expected growth to stay at the same Z-score, and for CDC 2–20 years BMI as a percent of the 95th percentile.
- On screen, values are rounded as on the calculator pages. The downloads (Excel or CSV) have every value unrounded, and dates as year-month-day (2026-03-02).
- A row that could not be calculated is kept, with a note saying why.