Full Term Baby Weight Calculator

How to Use This Calculator

To calculate your baby's expected weight:

1. Enter your baby's due date (or estimated due date)
2. Select your baby's sex (if known)
3. Enter your height and weight (for maternal factors)
4. Click "Calculate" to see the estimated weight

The calculator provides a range of expected weights based on standard growth charts and your personal factors. Remember that actual baby weight can vary significantly from these estimates.

Baby Weight Formula

The calculator uses a modified version of the Hadlock formula, which is commonly used for weight estimation:

This formula accounts for maternal factors and gestational age to provide a reasonable estimate. The result is presented as a range with a 90% confidence interval.

What Affects Baby Weight

Several factors influence a baby's weight at full term:

• Maternal factors: Height, weight, and body composition
• Gestational age: Babies born at 40 weeks are typically heavier than those born at 37 weeks
• Genetics: Family history of birth weight
• Nutrition: Maternal diet during pregnancy
• Activity level: More active babies may gain weight differently

These factors are considered in the calculator's estimation process.

Normal Weight Ranges

According to the World Health Organization, normal birth weight ranges are:

• Underweight: Less than 5.5 lbs (2.5 kg)
• Normal: 5.5-8.8 lbs (2.5-4.0 kg)
• Overweight: More than 8.8 lbs (4.0 kg)

The calculator provides estimates within these ranges based on your specific factors.

Preterm Babies

Babies born before 37 weeks are considered preterm. Their weight is typically lower than full-term babies. The calculator does not apply to preterm babies as it focuses on full-term estimates.

For preterm weight estimation, consider using a specialized calculator that accounts for gestational age differences.