Child BMI
Compute BMI for children and an approximate healthy weight range.
About Child BMI
BMI divides weight by the square of height in meters, then compares against broad bands, with a rough healthy weight range for the height. For children, percentile charts against age and sex are the gold standard, so treat this as a quick directional check, not a diagnosis.
Formula
Child BMI
BMI = weight(kg) / height(m) squared
- BMI
- Weight relative to height, unadjusted for age in this view
Worked example
With the default values below, Child BMI returns BMI of 16.0. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Weightminimum 0 kg
- 23 kg
- Heightminimum 1 cm
- 120 cm
- Sexone of Girl, Boy
- Girl
- Ageminimum 0 yr
- 7 yr
Results
- BMI
- 16.0
- Category
- Typical range
- Healthy Range Low
- 20.2 kg
- Healthy Range High
- 33.1 kg
Step by step
- 1Values used
- 2Child BMI
- 3BMI= 16.0
- 4Category= Typical range
- 5Healthy Range Low= 20.2 kg
- 6Healthy Range High= 33.1 kg
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Child BMI calculated?
BMI = weight(kg) / height(m) squared BMI divides weight by the square of height in meters, then compares against broad bands, with a rough healthy weight range for the height.
Why does Child BMI matter?
For children, percentile charts against age and sex are the gold standard, so treat this as a quick directional check, not a diagnosis.
What values do I need to enter?
This calculator takes 4 inputs: Weight, Height, Sex, Age. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.