Is this a safe pediatric dose for a medicine?

No. It is an educational comparison of dose-scaling rules. Real pediatric dosing must follow the exact medicine label, prescription or clinician/pharmacist instructions.

What is Clark's rule?

Clark's rule estimates a child dose as child weight divided by a 70 kg adult reference weight, multiplied by the adult dose. It is a rough historical rule, not a universal dosing method.

Why is body surface area included?

Some clinical dosing is based on body surface area, but drug-specific instructions still matter. BSA scaling cannot replace a product label or medical order.

Pediatric Dose Calculator

Compare historical pediatric dose-scaling rules from an adult single dose: Young's rule, Clark's rule, Fried's rule and body-surface-area scaling.

Educational comparison only: this calculator compares adult-dose scaling rules. It is not medication-specific prescribing, and it does not replace a drug label, prescriber, pharmacist, maximum-dose check, or product-concentration check.

Completed years

Additional months

Child weight, kg

Height, cm (optional)

Adult single dose from the label, mg

Use a single adult dose in mg only. Syrup ml, drops, or tablet counts depend on the concentration of the exact product.

Educational pediatric dose rule comparison

This calculator compares historical adult-dose scaling rules. It is not a safe pediatric dose recommendation for a specific medicine. Pediatric medicines need product-specific directions, age and weight limits, concentration checks and clinician or pharmacist review.

Young = \frac{a g e}{a g e + 12} \times adult dose

Age-based historical rule.

Clark = \frac{w e i g h t _{k g}}{70} \times adult dose

Weight-based adult-dose scaling using a 70 kg adult reference.

Do not use as pediatric prescribing advice

For a real child, use the drug label, prescription, pharmacist guidance or pediatric clinician instructions. Some medicines should not be scaled from adult doses at all.

Why pediatric dosing is high risk

Children may need dose caps, age limits or different intervals.
Liquid concentration changes the mL amount.
Acetaminophen and ibuprofen can be duplicated in combination cold products.
Kidney or liver problems can change whether a medicine is appropriate.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: June 2, 2026

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