Pediatric Weight Estimation
Estimate pediatric weight using validated APLS age-based formulas or Broselow length-based color zones. Essential for accurate medication dosing and equipment selection.
Pediatric Weight Estimation
Child (1-5 years)
12 kg
26.5 lb
Formula: (2.0 years × 2) + 8 = 12 kg
Broselow Zone Reference
Gray 46-55 cm 3.5 kg
Pink 55-67 cm 6 kg
Red 67-75 cm 8 kg
Purple 75-85 cm 10 kg
Yellow 85-95 cm 12 kg
White 95-107 cm 15 kg
Blue 107-115 cm 18 kg
Orange 115-124 cm 22 kg
Green 124-138 cm 30 kg
Important: These are estimates only. Actual patient weight
is always preferred. Use estimated weight only when actual weight cannot be obtained.
APLS Formulas:
- Infant (0-12 mo): (months + 9) / 2
- Child (1-5 yr): (years x 2) + 8
- Child (6-12 yr): (years x 3) + 7
References:
Advanced Paediatric Life Support (APLS), 6th Edition. BMJ Publishing Group.
Lubitz DS, Seidel JS, Chameides L, et al. A rapid method for estimating weight and resuscitation drug dosages from length in the pediatric age group. Ann Emerg Med. 1988;17(6):576-581.
When to Use
- • Actual weight is always preferred when obtainable
- • Use estimates for emergent medication dosing when weight is unknown
- • Length-based (Broselow) is generally more accurate than age-based
- • Age-based useful when patient cannot be measured (entrapment, etc.)
- • Caregiver-stated weight is more reliable than any estimation method
Limitations
- • Formulas may underestimate weight in obese children
- • APLS formulas less accurate outside 1-10 year range
- • Broselow tape not validated for children >36 kg
- • Neonatal weights vary significantly; use actual scale when available
- • Consider habitus when selecting equipment sizes
Safety Note
Weight estimation formulas provide approximations only and should never replace actual measured weight when it can be obtained. All medication doses calculated from estimated weights should be independently verified. Follow local protocols for pediatric weight estimation and medication dosing.