The short answer
From around six months, offer a few sips of water in an open cup with meals. NHS guidance gives no daily millilitre target; breast milk or first infant formula remains the main drink during the first year.
In this guide · 11 sections
Keep in mind
- Offer a few sips of water with meals from around six months.
- A US 120–240 mL daily guide is not a required target.
- Water must not replace breast milk or formula.
- Watch wet nappies, feeding and wellbeing as well as water intake.
Why offer water from six months?
In the first months, breast milk or correctly prepared infant formula provides your baby’s nourishment and fluids. Once solids begin, offer a few sips of water with meals as a new drinking skill, not as a replacement for milk.
Exploring a cup is as new as exploring food. Your baby may dribble water, grab the cup or refuse it at first. None of these reactions alone means your baby is not getting enough fluids.
How many millilitres of water a day?
NHS guidance does not set a daily millilitre target. At the start, a few sips with meals are enough for learning; gradually offer more as your baby eats a wider range of foods.
Keep breast milk or first infant formula as your baby’s main drink during the first year. Do not use water to replace milk feeds or dilute formula.
When during the day can you offer water?
An easy starting point is to offer a little water in a cup when your baby sits down to eat solids. Water then becomes part of the meal rather than replacing it. While your baby tastes soft cooked vegetables, bring the cup gently to their lips and let them sip at their own pace.
There is no need to insist on water after every spoonful. Let your baby explore even if they drink little. Make sure they are sitting upright and supervised in a calm setting.
Can water replace breast milk or formula?
No. Breast milk or suitable infant formula remains an important source of nutrition and fluids throughout the first year. Replacing milk feeds with water may reduce the energy and nutrients your baby receives.
If your baby leaves some of a bottle, do not top it up with water. Always follow the exact water-to-powder ratio on the formula packaging; extra water dilutes nutrients. If feeding is difficult, ask your baby’s healthcare professional for individual advice.
What if your baby refuses water?
Learning to drink water need not happen in one meal. Your baby may take a sip then turn away, or prefer playing with the cup. Refusing a few sips early in weaning does not, by itself, mean dehydration.
If your baby seems well, drinks their usual milk and is growing as expected, continue offering water gently. Unusually few wet nappies, marked tiredness or difficulty feeding deserve medical advice rather than treating the problem as cup training.
Which cup should you use?
The NHS suggests an open cup or a free-flow cup without a valve from around six months. It is natural for an adult to support the cup while the baby learns to take little sips.
Spills and wet clothes are part of learning. Focus on secure upright sitting and following your baby’s pace. Do not sweeten the water with sugar, juice or flavourings to persuade them to drink.
Does hot weather mean more water?
Fluid needs matter in hot weather, but do not replace milk with water or pressure your baby to exceed a general guide. A breastfed baby may want to nurse more often. WHO says exclusively breastfed babies under six months do not need additional water even in hot weather.
If your six-month-old has a fever, vomiting, diarrhoea or suspected dehydration, do not try to solve it by giving large amounts of plain water. Seek medical advice about assessing fluid loss and appropriate rehydration.
What can you try today?
If your baby has started solids and can sit upright, add a small open cup to a meal. Put a little safe drinking water in it, offer a few sips and stop when your baby has had enough. Try again at another meal without pressure.
At the end of the day, avoid focusing only on millilitres. Look at breast milk or formula intake, wet nappies, energy and overall wellbeing. Learning to use a cup is not a drinking contest.
When to seek support
Some signs need emergency help; other concerns can be discussed with your child’s healthcare team.
- Seek medical advice if your baby is unusually lethargic, has a dry mouth, markedly fewer wet nappies or cannot feed.
- Unresponsiveness or a major change in consciousness requires emergency help.
Sources used for this guide
- CDC — Foods and Drinks to Encourage
- NHS — Drinks and cups for babies and young children
- American Academy of Pediatrics / HealthyChildren.org — Choose Water for Healthy Hydration
- World Health Organization (WHO) — Breastfeeding – Questions and Answers
- WHO — Infant and young child feeding
English editorial review:
The English text and regional guidance have been checked editorially. This is not an individual clinical assessment.
Luluna provides general parenting information. It does not diagnose conditions or replace your child’s healthcare professional.
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