When can babies drink water?

For most babies, the usual starting point is around six months, once solid foods begin. Offer sips of water with meals rather than working towards a fixed daily amount.

Breast milk or first infant formula remains the main drink throughout the first year. Before six months, advice depends on how your baby is fed and their individual circumstances. The NHS hot-weather advice for some formula-fed babies does not apply to every baby.

Do not use water to replace a milk feed or dilute formula. If your baby is under six months, is unwell, has feeding difficulties or follows an individual feeding plan, ask a health visitor, GP or the professional supporting your baby before changing what they drink.

Why water starts alongside solid foods

The NHS recommends offering sips of water once a baby starts solid foods, usually around six months. The timing is tied to that feeding stage rather than an exact birthday.

Milk still does most of the work at this stage. Breast milk or first infant formula remains the main drink throughout the first year, while water is an additional drink offered with food. That does not mean every milk feed must stay exactly the same as eating develops, but water should not be used to replace a feed or to manage a feeding concern.

Breast milk or first infant formula remains the main drink through the first year; water with meals is additional.

The aim is gentle practice, not reaching a target. Support your baby while they learn to drink in a new way.

What about water before six months?

There is more to consider before six months. How your baby is fed, hot weather, their health and any individual advice all matter.

If your baby is fully breastfed

A fully breastfed baby does not normally need water before starting solid foods. In hot weather, they may want to breastfeed more often. Continue to offer the breast responsively rather than routinely adding water.

If your baby is formula-fed

In hot weather, a formula-fed baby under six months may need small sips of cooled boiled water as well as their usual milk feeds. This is conditional hot-weather advice, not a reason to replace milk or give every younger baby water.

Never add extra water to a formula feed. Make each feed using the proportions on the manufacturer's instructions.

When to ask for individual advice

There is no single rule for a mixed-fed baby under six months. Ask a health visitor or GP what is appropriate for your baby, particularly in hot weather.

Ask for individual advice too if your baby was born prematurely, has a medical condition, has difficulty feeding or is following a plan from a clinician or feeding team. Advice from professionals who know your baby takes priority over general guidance.

How to offer water safely with meals

Start with supported sips

From around six months, offer sips at mealtimes in a small open cup or a free-flow cup or beaker without a valve. Help your baby hold the cup while they learn.

There is no single daily target that applies to every baby. Offer sips with meals rather than trying to make a young baby finish a set amount.

Offer sips with meals and help with the cup while your baby learns to drink from it.

Drinking water is not formula-preparation water

For a baby over six months, drinking water does not need to be boiled first. This does not change the separate rules for making powdered formula, and it does not apply to the hot-weather advice about cooled boiled water for some formula-fed babies under six months.

Follow the NHS formula-preparation guidance and the manufacturer's instructions exactly. Never add extra water or make a feed weaker. If you are unsure about bottle feeding or preparation, ask a midwife, health visitor, GP or the clinical team supporting your baby.

Illness, dehydration signs and when to get help

Possible dehydration signs are prompts to get an assessment, not a way to diagnose your baby at home. A change from what is normal for your baby, such as fewer wet nappies or unusual drowsiness, matters more than trying to match a fixed checklist or nappy count.

If you are very worried about a baby under six months, NHS guidance notes that young babies can be difficult to assess by phone. Seek urgent in-person assessment at an urgent treatment centre or A&E.

If your baby has vomiting or diarrhoea

Continue breast or bottle feeds. If your baby is vomiting, smaller feeds more often may be appropriate. Babies who are formula-fed or eating solid foods may have small sips of water between feeds, but plain water is not a treatment for dehydration and formula must not be weakened.

The NHS advice on diarrhoea and vomiting explains when to call 111 or seek emergency help. If an oral rehydration solution may be needed, ask a pharmacist or another suitable health professional what is appropriate rather than making a homemade mixture or guessing a dose.

Routine feeding concerns

Speak to a health visitor or GP about persistent feeding difficulty, frequent or forceful vomiting, apparent pain, slow weight gain or another ongoing concern. Adding water or diluting formula is not a substitute for an individual assessment.

This article offers general UK information. It cannot confirm or rule out dehydration, diagnose an illness or feeding problem, or override professional advice for your baby.

Questions about giving a baby water