Baby weight calculator

Estimate your baby's weight based on gestational age using WHO growth standards

Input Parameters

Calculation Results

Estimated Weight

-- kg
Calculation Formula

Weight = a * (GA)^b + c

Where:
GA = Gestational Age in weeks
a, b, c = Gender-specific parameters from WHO growth standards

*This calculator uses WHO growth standards for term infants based on gestational age.

*For preterm infants or special cases, consult with healthcare professionals.

Baby weight calculator Calculator Usage Guide

Learn how to use the Baby weight calculator and its working principles

How to use the calculator

  1. Enter your baby's gestational age in weeks (from conception or last menstrual period).
  2. Select your baby's sex (male or female).
  3. If your baby was born, you can optionally enter their birth weight in grams for a more personalized estimate.
  4. Click the "Calculate" button to get an estimated weight based on WHO growth standards.
  5. The calculator provides an estimated weight in kilograms at the current gestational age.

Working principles

This calculator uses the World Health Organization (WHO) growth standards for term infants. The estimation is based on a mathematical formula that relates gestational age to expected weight, with different parameters for male and female infants.

The formula used is:

Weight (grams) = a × (GA)^b + c

Where GA is the gestational age in weeks, and a, b, and c are gender-specific parameters derived from WHO growth data.

Important note: This calculator provides estimates based on population averages. Actual baby weight may vary based on individual factors. Always consult with healthcare professionals for accurate assessments and monitoring.