Baby Calculators

Tools and calculators for the care and development tracking of your baby.

Baby Feeding Calculator

Calculate how much milk your baby needs based on weight and age. Recommended feeds, milliliters per feed, and hunger and fullness cues.

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Baby Size Converter

Convert baby clothing sizes between Zara, H&M, Primark, Carter's, Kiabi, Mango, and Mayoral. Enter your baby's height and weight to get the exact size for each brand.

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WHO Percentile Calculator for Babies

Calculate your baby's weight, height and BMI percentile using WHO growth charts (0-5 years).

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Fertile Days Calculator

Calculate your fertile window and ovulation date based on your menstrual cycle.

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Pregnancy Weeks Calculator

Calculate exactly which week of pregnancy you are in, your trimester, and your estimated due date.

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Baby Vaccination Calendar in Spain

Calculate the exact vaccination dates for your baby according to the AEP 2026 schedule.

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Available tools

Feeding calculator by age and weight
Growth percentile calculator (WHO)
Baby clothing size converter by brand
Fertile days estimator
Personalized vaccination calendar
Pregnancy and gestational weeks calculator

# Tracking your baby's development

Baby calculators help you accurately track your child's growth and development. From calculating milk feeds based on age and weight to checking WHO percentiles, these tools are designed to give you useful information at every stage.

# Feeding and nutrition

The feeding calculator estimates the amount of breast milk or formula your baby needs based on their age in days, weeks, or months and their current weight. Calculations follow standard pediatric guidelines to ensure adequate nutrition.

# Growth and percentiles

The percentile calculator uses the World Health Organization (WHO) reference tables to place your baby's weight, height, and BMI within the distribution of the child population. A 50th percentile indicates the baby is at the average.