How much should baby gain and what’s normal in their diaper?

Short answer: babies gain weight in a fairly predictable pattern, and their poop changes a lot in totally normal ways in the first weeks. Here's what to expect, so you can stop Googling at 3am and get back to sleep.

Weight Gain By Age

  • Some weight loss is expected and normal. No further loss should happen after day 5.

  • About 1 oz (30 g) per day on average, once your milk is in and baby is back to birth weight.

  • 8–9 oz per week

  • 7–10 oz per week

  • 5–7 oz per week

  • 4–6 oz per week

  • 2–5 oz per week, or about 12–22 oz per month

  • 2–4 oz per week, or about 9–18 oz per month

  • About 7–16 oz per month

  • About 4–13 oz per month

Why the range is wide: growth naturally slows down as babies get older, and it's rarely a straight line even week to week, growth spurts and quieter stretches both happen. If you're ever unsure where your baby falls, bring it to our visit and we'll look at their growth chart together.

What’s A Normal Diaper?

Poop changes color, texture, and frequency a lot in the early months almost all of it is normal

  • Thick, tar-like, dark green-black (meconium). This clears out over the first few days.

  • Transitioning — greenish-brown, looser, in between meconium and mature milk stool.

  • Yellow, seedy, and loose is the classic breastmilk stool. Often described as looking like mustard with seeds. Totally normal, even if it seems like a lot.

  • Frequency can drop off a lot. Some breastfed babies go several days, even up to a week or more, between stools once they're older. As long as it's soft when it comes and baby seems comfortable, this is usually normal too.

Worth a call to your baby's doctor

  • Fewer than 5 wet diapers a day after day 5

  • Blood in the stool

  • Concentrated or dark, strong-smelling urine

  • No stool for several days in a younger baby who hasn't yet settled into a pattern, especially alongside straining, discomfort, or a hard belly

  • Anything that just doesn't sit right with your gut — you know your baby, and you never need a "good enough" reason to ask

Good signs of hydration & intake

5–6 heavy wet diapers and 3–4 stools the size of a quarter or larger in 24 hours (in the earlier weeks) are reassuring signs your baby is getting enough.