Baby Weight Tracking: How to Read a Growth Chart

What Percentiles Actually Mean

A growth chart compares your baby to a reference population of the same age and sex. Staying on top of these tracking appointments can be a challenge for busy families — the working parents guide has practical tips for scheduling and sharing health responsibilities. The 50th percentile is the median — half of babies are above, half below. Being at the 10th percentile doesn't mean your baby is unhealthy; it means they're on the smaller end of normal. What matters most is the trend over time, not any single measurement (WHO Child Growth Standards, 2006).

Consistent tracking along a percentile line — even a low one — signals healthy growth. It's sudden drops or climbs across two or more major percentile lines that warrant evaluation.

Normal Weight Gain by Age

• 0–3 months: About 5–7 oz (150–200 g) per week. Most babies double their birth weight by 4–5 months.
• 3–6 months: About 3.5–5 oz (100–150 g) per week.
• 6–12 months: About 2.5–3 oz (70–90 g) per week — growth naturally slows. This is normal and not a feeding problem.
• 1–2 years: About 7–8 oz (200–250 g) per month. Most babies triple their birth weight by 12 months.

Growth Spurts

Growth spurts typically occur around 2–3 weeks, 6 weeks, 3 months, and 6 months. During these periods babies nurse more frequently, seem fussier, and may sleep differently. This is the baby's way of increasing milk supply — not a sign that supply has dropped. Spurts typically last 2–4 days.

When to Be Concerned

• Has not regained birth weight by 2 weeks of age
• Drops across two or more major percentile lines
• Fewer than 6 wet diapers per day (in babies under 6 weeks)
• Persistent crying and apparent hunger after every feeding