How much breast milk to express

The amount of breast milk you need to express, and how often you express, will depend on the situation. For example, you may need to express more for your newborn baby if they are unable to breastfeed.

The amount you express for an older baby will depend on the number of times they breastfeed each day.

Important

These amounts are only a guide.

If your baby is born sick or premature, you may not reach this volume.

Any amount that you can express for your baby is helpful. Your midwife, lactation consultant or public health nurse (PHN) can help you.

Expressing breast milk for premature or ill babies

Newborn babies

If you need to express milk for your baby in the early days after birth, here's a guideline on what to expect:

Day Milk expressed in 24 hours How much your baby will get at a feed
Day Day 1 Milk expressed in 24 hours 7ml to 123ml How much your baby will get at a feed from a few drops to 5ml (5ml is approximately 1 teaspoon)
Day Day 2 Milk expressed in 24 hours 44ml to 335ml How much your baby will get at a feed from 5ml to 15ml
Day Day 3 Milk expressed in 24 hours 98ml to 775ml How much your baby will get at a feed from 15ml to 30ml

With time and practice, it will become easier and the amount of milk you express will increase.

How to express breast milk

How much milk a growing baby needs

In exclusively breastfed babies (babies who are fed breast milk only), milk intake increases quickly during the first few weeks of life.

How much milk a baby consumes will change as they get older and grow bigger.

During the first week, most full-term babies take no more than 1 to 2 ounces (30 to 60 ml) at feedings. This is because newborns’ stomachs are so small.

After 4 to 5 weeks, babies reach their peak feeding volume of about 3 to 4 ounces (90 to 120 ml) and peak daily milk intake of about 30 ounces per day (900 ml). This should stay about the same between 1 and 6 months, although it generally increases short-term during growth spurts.

After 6 months, your baby’s milk intake begins to decrease gradually as you introduce solid food.

Expressing for time away from baby

Research tells us that exclusively breastfed babies take in an average of 25 oz (750 ml) per day when they are 1 to 6 months old. A typical range of milk intake is 19 oz to 30 oz (570 ml to 900 ml) per day.

Use these steps to work out the amount of breast milk your baby will need:

  1. Estimate the number of times that your baby breastfeeds per day (in 24 hours).
  2. Divide 25 oz (750 ml) by the number of breastfeeds.
  3. This gives you a rough guide for the amount of expressed milk your exclusively breastfed baby will need at one feeding.

For example, if your baby usually breastfeeds around 8 times per day, you can guess that they might need around 3 oz (94 ml) of expressed breast milk per feeding.

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 8.

Page last reviewed: 2 May 2022
Next review due: 2 May 2025