Enter child's age in years, from 0 to 12
Enter additional months, from 0 to 12
Check this if you know the child's actual weight
Check this to calculate for cuffed endotracheal tube, which reduces internal diameter by 0.5mm

Frequently Asked Questions

This WETFLAG calculator supports children from 1 month to 12 years of age. For infants 1-12 months, we use the formula (0.5 × months + 4) kg. For children 1-5 years, we use (2 × age + 8) kg, and for 6-12 years, we use (3 × age + 7) kg. These formulas are aligned with UK paediatric Advanced Life Support (APLS) and RCUK guidelines.

Current UK guidance increasingly favours cuffed tubes for paediatric intubation as they provide better seal and reduce the need for tube changes. The calculator uses the formula (age/4 + 4) mm for uncuffed ETT internal diameter. If you select "Use cuffed ETT", it subtracts 0.5 mm from the result. Always check your local PICU or ED policy, as practice varies.

Yes, this calculator is designed to align with Resuscitation Council UK (RCUK) paediatric guidelines and Advanced Paediatric Life Support (APLS) / European Paediatric Advanced Life Support (EPALS) protocols. The weight estimation formulas, defibrillation energy (4 J/kg), fluid bolus (20 mL/kg), and drug dosing are based on current UK paediatric emergency medicine standards. However, always verify against your local hospital policy.

The calculator shows a practical cap of 150 J for initial defibrillation shocks in paediatric cardiac arrest, following RCUK guidance. While the 4 J/kg calculation may yield higher values for larger children, 150 J is typically recommended as the maximum for the first shock with biphasic defibrillators. Subsequent shocks may be escalated according to your resuscitation algorithm. Always follow your local paediatric resuscitation protocols.

Absolutely! If you have the child's actual weight (from recent weighing, parent report, or medical records), check the "I know the weight" box and enter the weight in kilograms. Known weight will always supersede the age-based estimation and provide more accurate drug and fluid calculations. In emergency situations where weight is unknown, the age-based formulas provide safe estimates based on UK paediatric population norms.

Local hospital policies and trust guidelines may vary in drug concentrations, dosing strategies, or preferred routes of administration. This calculator provides estimates based on standard UK paediatric emergency medicine practice, but you must always confirm doses and routes with your local emergency department, PICU, or trust formulary. Use this tool as a quick reference guide, not as a substitute for clinical judgment or local protocols. When in doubt, consult your senior clinician or resuscitation team.