New to expressing and need to know the basics?
Mums express breastmilk in many different ways and for many different reasons. Milk can be removed by hand or using a manual or electric breast pump.
Your method of expressing may depend on your situation and how much you need to express. An electric breast pump may suit you best if you are expressing for a premature baby, you’re planning to go back to work or you trying to increase your milk supply. Situations like these require frequent expressing sessions to collect large amounts of milk.
If you will be expressing smaller amounts of milk or expressing here and there, e.g. to have milk available when leaving your baby, you may find a manual breast pump is adequate. You could also hand express in situations like these.
Your questions answered
If you are exclusively expressing for all your baby's feeds you will need to express more milk than a mum who is just expressing for the occasional feed when she is away from her baby.
Whatever your situation, you can work out how much milk your baby may need as a start to knowing how much to express. Research tells us that breastfed babies between 1 and 6 months of age take an average of 750 mL per day, although some may need less and some more.1,2 You can use this amount as a guide to help you know how much you may need to express and leave for your baby:
1. To work out the volume of a single feed, divide 750 mL by the number of feeds your baby usually has in 24 hours.
2. Multiply this amount by the number of breastfeeds you will be missing.
As an example, if your baby has 10 feeds in 24 hours, then 750 mL divided by 10 equals 75 mL per feed. If you think they will miss 3 breastfeeds while you are away, the total amount of milk you leave will need to be 3 x 75 mL, which is 225 mL.
How often you need to express will depend on how much you are able to express at a time. If you are exclusively expressing milk to feed your baby you should aim to express often (at least 8 times in 24 hours). At first, you may find it easier to pump for shorter periods but more often. Many mums find a routine of expressing every 2 to 3 hours during the day, with a session just before going to bed, works for them.
Try to avoid any long gaps (more than 6 hours) between expressing sessions if you are building up a milk supply.3 This means you may need to express once or twice at night too. Milk supply and response to expressing vary between mums, so you may have to try different timing to find a pattern that suits you.
Mums vary in the amount of time it takes them to express. The length of time depends on many factors (time of the day, technique used, pump type and setting, and your flow rate). The number of times you express during the day is often more important than the length of time you spend expressing.
It can take a minute or two for the milk to begin flowing freely, or 'let down', when you express. If you can touch, see or hear your baby this may help. There are also extra steps you can try when expressing to help the milk to flow.
An expressing session usually goes for about 15 to 20 minutes, or until milk no longer flows out but just drips. Keep going for a few minutes past when your milk stops flowing, as this might trigger another let-down. Some may need a little more or a little less time. But for most mums, pumping for more than 30 minutes is too long.
Some mums who are expressing regularly can quickly get a large amount of breastmilk from each breast. Other mums find it easier to express small amounts more frequently (eg up to 30 mL every 1-2 hours).
It’s important not to judge how much milk you are making by the amount of milk you can express. Pumping and hand expressing are skills that can take time to learn. If your baby is feeding well, they will take more milk from your breast, and more quickly, than you will by pumping or hand expressing.
Is expressing the best option for me?
There are some things to think about when deciding if expressing is right for you.
- Expressing isn’t always needed. Many breastfeeding mums never need to express and their babies never need expressed breastmilk. They find that breastfeeding fits in with their daily lives including social activities, work and study.
- Expressing takes time and energy. It can be hard to find the time to express when you are caring for a young baby. If you use a breast pump it takes extra time to set-up and clean the equipment.
- It can increase your supply unnecessarily. Removing more milk than your baby needs each day can create an oversupply. This can increase your risk of breast inflammation.
- It takes practice. It can take time to learn how to hand express or use a breast pump. A few mums find it difficult to express any milk even though they have a good supply and their baby is growing well.
- Expressing may not fix an underlying problem. Some mums think about expressing because breastfeeding isn’t going well. Getting help and support with any breastfeeding problems may be a better long-term fix.
Depending on your reasons for expressing, there may be other more helpful options available to you. Speak to an ABA breastfeeding counsellor to work out a plan for your situation. If you decide to express, you might wonder about the following questions.
© Australian Breastfeeding Association June 2025
Rios-Leyvraz, M., & Yao, Q. (2023). The volume of breast milk intake in infants and young children: A systematic review and meta-analysis. Breastfeeding Medicine, 18(3), 188–197.
Kent, J. C., Mitoulas, L. R., Cregan, M. D., Ramsay, D. T., Doherty, D. A., & Hartmann, P. E. (2006). Volume and frequency of breastfeedings and fat content of breast milk throughout the day. Pediatrics, 117(3), e387–e395.
Lai, C. T., Rea, A., Mitoulas, L. R., Kent, J. C., Simmer, K., Hartmann, P. E., & Geddes, D. (2020). Short-term rate of milk synthesis and expression interval of preterm mothers. Archives of Disease in Childhood. Fetal and Neonatal Edition, 105(3), 266–269.
Read more about expressing and storing
Evidence-led info and practical tips from our Breastfeeding Information Series
