Baby's weight: what’s normal and how to keep track

Seeing your baby on the scale can feel like a mini heart attack or a relief — often both. Here’s a clear, practical guide to newborn and infant weight so you know what to expect, how to measure progress, and when to reach out for help.

What to expect in the first weeks

Most newborns lose 5–10% of birth weight in the first 3–5 days. That’s normal. They usually regain birth weight by 10–14 days. After that, typical gains are about 20–30 grams (0.7–1 oz) per day for the first few months, or roughly 150–200 grams (5–7 oz) a week in month one. Growth slows a bit after 3–4 months.

Birth weight varies a lot. Full-term babies often weigh 2.5–4.0 kg (5.5–8.8 lb). Premature babies and those with medical issues will follow different patterns — your pediatrician will give targets for them.

How to track weight the smart way

1) Use growth charts. Your pediatrician plots weight, length, and head circumference against WHO or CDC growth charts. Percentiles show whether your baby follows a consistent curve. A baby who’s consistently on the 10th percentile is fine if they stay there.

2) Weigh at consistent times. Use the same scale, with the same clothing (or naked) and time of day for accurate comparisons. Home scales vary, so small changes don’t always mean much.

3) Keep a log. Write down weight, feeding patterns, and diapers. Good weight gain plus regular wet diapers means feeding is likely going well.

4) Watch feeding, not just numbers. Breastfed babies may feed more often and gain weight differently than formula-fed babies. If feeds are frequent, poops and pees look normal, and baby seems satisfied after feeds, chances are growth is fine.

5) Ask for a weight check. If you worry, ask the clinic for a nurse visit to weigh baby on a medical scale.

6) Growth spurts happen. Expect jumps after periods of slower gain. These are normal and often linked to feeding changes or developmental leaps.

When to be concerned and call your pediatrician

- Baby loses more than 10% of birth weight or doesn’t regain birth weight by 2 weeks. - Weight falls across two or more major percentile lines on the growth chart. - Fewer than 6 wet diapers a day after day 5, or very little urine output. - Baby seems lethargic, uninterested in feeds, or is vomiting often. - Signs of dehydration: dry mouth, sunken soft spot, very few wet nappies.

These signs don’t always mean something serious, but they do need a prompt check.

Final practical tip: trust trends over single numbers. One low or high weight isn’t the story — the pattern is. If you’re unsure, call your pediatrician. They’ll help you interpret the chart and suggest feeding or medical steps if needed. You don’t need to figure this out alone.