Hydration while breastfeeding: how much to drink

2026-10-30

While you're breastfeeding, you need roughly 600 to 700 ml (20 to 24 fl oz) more water a day than usual, according to the European Food Safety Authority. That brings a typical adequate intake to about 2.6 to 2.7 liters (88 to 91 fl oz) of total water from food and drinks. The good news: your thirst rises to match, so for most healthy mothers "drink when you're thirsty, and keep a drink within reach while you feed" covers it. Drinking far more than you need does not increase your milk supply.

How much extra water breastfeeding takes

Breast milk is almost 90% water, and an exclusively breastfed baby drinks on average around three-quarters of a liter a day once feeding is established. That water has to come from somewhere, which is why reference values go up:

EFSA (Europe): an adequate intake of 2.0 liters of total water a day for women, plus 600 to 700 ml while breastfeeding, so about 2.6 to 2.7 liters.
National Academies (US): 3.8 liters of total water a day during lactation, of which about 3.1 liters (around 13 cups) comes from drinks.

The two figures differ because they were derived differently, and both describe what healthy breastfeeding women typically take in, not an exact target. "Total water" includes the water in food, which usually provides around a fifth of it (see how much of your water comes from food). For background on the reference values for everyone else, see how much water you should drink a day.

Your needs also depend on how much you're feeding: exclusive breastfeeding of a young baby takes more than one or two feeds a day alongside solids. Twins, hot weather and exercise all push the number up.

Thirst is a good guide here

Many women notice a sudden wave of thirst soon after the baby starts feeding. For healthy adults, thirst is a reliable signal, and your body is quite good at asking for what it needs.

That's why the practical advice from health services is simple. The NHS suggests keeping a drink nearby when you sit down to breastfeed, and names water, lower-fat milk or diluted fruit juice as good choices. No measuring cup required.

Where thirst falls short is when you're too busy or too tired to notice it, which describes much of early parenthood. If you realize at 4 p.m. that you've had one cup of coffee all day, thirst hasn't failed you; you just didn't have a hand free.

Myth: drinking more water makes more milk

This one is widespread and understandable, but the evidence doesn't support it. Milk supply is driven mainly by demand: how often and how effectively milk is removed from the breast.

A Cochrane review on extra fluids for breastfeeding mothers found no proper randomized trials. The one small, older trial it could include reported that advising extra fluids did not increase milk production. The reviewers concluded there isn't enough evidence to recommend drinking beyond what your body needs. The evidence is thin, but there's also no plausible mechanism by which forcing down extra liters would help.

What does matter:

Not getting dehydrated. Running low on fluids isn't good for you, and you'll usually feel it: thirst, headache, tiredness, dark urine.
Frequent, effective feeding or pumping. If you're worried about supply, talk to your midwife, health visitor, pediatrician or a lactation consultant. They can check latch, feeding frequency and your baby's weight gain, which tell you far more than how much you drank.

Drinking very large amounts on purpose can even backfire, since excess water mostly ends up as urine and, in extreme cases, can dilute your blood sodium (see can you drink too much water?).

What to drink

Water is the default.
Milk and fortified plant drinks add protein and calcium.
Tea and coffee count. Caffeine passes into breast milk in small amounts. The CDC describes up to about 300 mg a day, roughly 2 to 3 cups of coffee, as low to moderate and usually fine for the baby. Very high intakes have been linked to a fussy, jittery or poorly sleeping baby, and newborns and premature babies clear caffeine more slowly, so you may want less in the early weeks.
Juice and soft drinks hydrate but add sugar; keep them occasional.
Alcohol passes into breast milk. If you choose to drink, health services advise keeping it occasional and timing it away from feeds; it doesn't count toward hydration.
"Lactation teas" with herbs like fenugreek are marketed for supply, but good evidence is lacking. Check with a health professional before using herbal products.

Signs you need more

You're thirsty much of the time.
Your urine is dark yellow, or you're peeing much less than usual (see what your urine color says).
Headaches, dizziness, constipation or unusual tiredness. Sleep deprivation causes plenty of these too, but it's worth ruling out the easy fix.

If you have a fever, vomiting or diarrhea, your needs go up sharply; an oral rehydration solution can help (see what to drink when you're sick), and you can usually keep breastfeeding. Contact a doctor if you can't keep fluids down or feel faint.

Easy ways to keep up

Set up a feeding station. A large bottle at every spot where you feed: sofa, bed, nursing chair. Refill it whenever you get up.
One glass per feed. Ten feeds a day is a lot of glasses, so even half of them gets you most of the way.
Use a bottle you can open with one hand. A straw or a flip lid makes a real difference with a baby in your arms.
Eat water-rich foods. Soups, fruit, yogurt and smoothies are easy to manage one-handed and count toward your total.
Ask for help. Partners and visitors can bring water every time they bring the baby.

Logging also helps when days blur together. In Water Tracker you can raise your daily goal by about 600 to 700 ml (20 to 24 fl oz) in Settings, and log a glass with one tap from a Home Screen widget, from Siri, or from your Apple Watch without picking up your phone. Reminders stop as soon as you've reached your goal, so they won't keep nagging you once you're done.

When to talk to someone

Talk to your doctor if you have a condition that affects fluid balance, such as kidney or heart disease, or if you've been told to limit fluids. Talk to a midwife, health visitor or lactation consultant if you're worried about your milk supply or your baby's feeding, wet diapers or weight gain.

The bottom line

Breastfeeding raises your water needs by about 600 to 700 ml (20 to 24 fl oz) a day, for a total of roughly 2.6 to 2.7 liters from food and drinks according to EFSA. Keep a drink within reach at every feed, follow your thirst, and watch your urine color. Extra water beyond that won't increase your supply; frequent, effective feeding does.

This article is general information, not medical advice. If you have a health condition, are pregnant or take medication, ask your doctor how much you should drink.