# Who Growth Charts

> Generate WHO child growth charts (height, weight, BMI) with percentile curves. Downloads official WHO reference data on demand. Use when users ask about child growth tracking, percentiles, or want growth charts for their kids.

- Skill: `modbender/who-growth-charts` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add modbender/who-growth-charts`
- Raw SKILL.md: https://api.skillmd.com/api/skills/modbender/who-growth-charts/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Marketing & Growth
- Author: modbender (https://skillmd.com/u/modbender)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/modbender/who-growth-charts

---


Generate WHO Child Growth Standards charts with percentile curves and child data overlay.

## Features

- **Height-for-age** (0-19 years)
- **Weight-for-age** (0-10 years)
- **BMI-for-age** (0-19 years)
- Supports **boys and girls**
- **Downloads WHO data on demand** from cdn.who.int (cached locally)
- Overlays child's actual measurements with trend line

## Examples

| Height | Weight | BMI |
|--------|--------|-----|
| <img src="examples/anna_height.png" width="250"> | <img src="examples/anna_weight.png" width="250"> | <img src="examples/anna_bmi.png" width="250"> |

## Prerequisites

Install Python dependencies:
```bash
pip install pandas matplotlib scipy openpyxl
```

## Usage

### Basic Chart Generation

```bash
python3 ./scripts/growth_chart.py "Child Name" "DD.MM.YYYY" --sex F --type all
```

Arguments:
- `name`: Child's name (used in chart title)
- `birthdate`: Date of birth in DD.MM.YYYY format
- `--sex` / `-s`: `F` (female) or `M` (male) — default: F
- `--type` / `-t`: `height`, `weight`, `bmi`, or `all` — default: all
- `--data` / `-d`: JSON file with measurement data
- `--output` / `-o`: Output directory for charts

### With Measurement Data

Create a JSON file with height/weight measurements (heights in meters, weights in kg):
```json
{
  "heights": [ ["2024-01-15T10:00:00", 1.05] ],
  "weights": [ ["2024-01-15T10:00:00", 17.5] ]
}
```

```bash
python3 ./scripts/growth_chart.py "Emma" "06.07.2016" --sex F --data emma_data.json --type all
```

### Integration with Withings

Combine with `withings-family` skill to fetch weight data automatically:
```bash
# Get Withings weight data (assuming withings-family skill is installed)
python3 ../withings-family/scripts/withings.py emma body > /tmp/withings.json

# Parse and generate charts
# (The growth chart script handles Withings JSON format if implemented, otherwise transform it)
```

## Output

By default, charts and cache are written to:

- `<workspace>/who-growth-charts/`
- `<workspace>/who-growth-charts/cache/`

Where `<workspace>` is the folder that contains your `skills/` directory (the script finds it automatically; it also prefers the current working directory if it looks like a workspace, which makes symlinked workspaces behave correctly).

You can override workspace discovery with `WHO_GROWTH_CHARTS_WORKSPACE=/path/to/workspace`.