How is a child's weight estimated from age?

The APLS formulas estimate weight: under 1 year, (0.5 × age in months) + 4; 1–5 years, (2 × age in years) + 8; 6–12 years, (3 × age in years) + 7. These are estimates only — a measured weight is always preferred where possible.

Does this tool give paediatric drug doses?

No. It intentionally provides no drug doses. Use the estimated (or, preferably, measured) weight to look up every dose in a children's formulary at the point of prescribing.

Paediatric Weight Estimator

Estimate a child's weight from age (APLS formulas) for resuscitation planning.

Important — paediatric safety

This gives an estimated weight only; a measured weight is always preferred. This tool does not provide drug doses — use the weight to look up every dose in a children's formulary at the point of prescribing. Decision support only; apply clinical judgement and resuscitation guidelines (APLS/EPLS).

Age — yearsmonths

Enter a child's age to estimate weight.

The APLS weight formulas

Under 1 year: weight (kg) = (0.5 × age in months) + 4
1–5 years: weight (kg) = (2 × age in years) + 8
6–12 years: weight (kg) = (3 × age in years) + 7

Airway sizing (uncuffed endotracheal tube, ~1–10 years): internal diameter (mm) = age/4 + 4; length at lips (cm) = age/2 + 12. These are starting estimates to be confirmed clinically.