Calculates Body Mass Index (BMI) for children and teens (ages 2-20) and shows the corresponding BMI-for-age percentile based on CDC growth charts. This tool helps parents and guardians track their child's growth and understand their weight status (e.g., Underweight, Healthy Weight, Overweight) relative to their peers. It includes a visual chart to plot the child's BMI against the standard growth curves, providing a clear, intuitive representation of their development. The tool supports both Metric and Imperial units, and all data is saved privately in the user's browser.