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Paediatric Dose (Young Rule) Calculator

Work out paediatric dose (young rule) instantly with clear inputs, formula shown and shareable results.

About Paediatric Dose (Young Rule) Calculator

Applies Young's rule, which scales an adult dose by age divided by age plus twelve for children aged one to twelve.

Formula

Young's rule

Child dose = adult dose x age (years) / (age + 12)

Worked example

With the default values below, Paediatric Dose (Young Rule) Calculator returns Estimated child dose of 166.7. Change any input above and every figure here is recalculated in your browser.

Inputs used

Adult doseaccepts 1–5,000 mg
500 mg
Child ageaccepts 1–12 years
6 years

Results

Estimated child dose
166.7 mg
Age fraction applied
0.333
Share of the adult dose
33.3%

Step by step

  1. 1Values used
  2. 2Young's rule
  3. 3Estimated child dose= 166.7 mg
  4. 4Age fraction applied= 0.333
  5. 5Share of the adult dose= 33.3

Assumptions and limits

  • The result is derived only from the 2 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 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
  • Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
  • This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.

Frequently Asked Questions

What age range does it cover?

One to twelve years. Outside that range it has no validity.

Why is weight-based dosing preferred?

Children of the same age vary widely in size, so weight or body surface area tracks drug handling far better.

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