Most healthy adults do not need to count every sip: the NHS guide is to aim for 6 to 8 cups or glasses of fluid a day. This article explains which drinks count towards that, how to tell whether you are drinking enough, and when it is worth getting advice.
What is the official guide for daily fluids?
According to the NHS, the Eatwell Guide recommends that people aim to drink 6 to 8 cups or glasses of fluid a day. It is a guide rather than a target to hit exactly, and nothing in it suggests that one day at five glasses or nine is a problem for a healthy adult.
The same NHS page says some people may need more. It names being pregnant or breastfeeding, being in a hot environment, being physically active for long periods, and being ill or recovering from illness. In those situations the body loses or uses more fluid, so a fixed number of glasses is a starting point rather than a ceiling.
Note what the guide does not say. It does not set a single figure in litres for everyone, and it does not claim that drinking far more than the range brings extra benefits. A steady, regular intake across the day is the sensible aim.
Which drinks count towards your total?
The NHS says water, lower-fat milk and lower-sugar drinks, including tea and coffee, all count. Unsweetened plant-based drinks are also an option for adults. Some of your fluid also comes from food, which is part of why the guide gives a range rather than a precise amount.
That is good news for anyone who has been told that tea and coffee “do not count”. On the NHS guidance, they do, provided they are lower in sugar and taken in moderation. Our piece on caffeine, alcohol and timing in the evening covers the separate question of when stimulant drinks are best avoided.
A worked example of a typical day
Illustrative arithmetic shows how quickly the total builds up without anything unusual:
| Time | Drink | Count |
|---|---|---|
| Breakfast | Tea | 1 |
| Mid-morning | Coffee | 1 |
| Lunch | Glass of water | 1 |
| Afternoon | Glass of semi-skimmed milk in tea or on its own | 1 |
| Late afternoon | Glass of water | 1 |
| Evening meal | Diluted sugar-free squash | 1 |
| Evening | Herbal tea | 1 |
That makes 7 cups or glasses, comfortably inside the 6 to 8 range, without a single bottle of water being carried around.
How can you tell if you are drinking enough?
The NHS gives a simple, practical test: aim to drink enough during the day that your pee is a clear pale yellow colour. It is a rough indicator, not a laboratory measure, but it is easy to check and costs nothing.
A few cautions help keep the test in perspective:
- Dark yellow, strong-smelling pee is listed by the NHS as a sign of dehydration.
- Some things change urine colour for reasons unrelated to fluids, so one odd-looking visit to the toilet is not a diagnosis. If a change in colour persists and you cannot explain it, raise it with a pharmacist or GP.
- Thirst, a dry mouth and a headache are other common signs that you may need to drink more, according to the NHS.
Because pee colour reflects what is happening over the past few hours, a quick glance in the morning and again mid-afternoon is usually enough to prompt a top-up.
Why do sugary drinks and juice need a second look?
The NHS advises that adults avoid having drinks that are high in sugar too often, and that children avoid sugary fizzy drinks, squash and juice drinks completely. It recommends swapping to diet, sugar-free or no-added-sugar versions where you can.
Fruit juice and smoothies are a common trap because they feel healthy. The NHS says to limit them to a maximum of one small glass, which it puts at 150ml, a day, and to drink it with a meal. The wider picture on sugar is covered in our guide to free sugars and where they hide.
Illustrative arithmetic: if you have one 150ml glass of juice at breakfast, it can count as one of your cups or glasses, but a second and third glass later in the day would take you past the NHS limit for juice, even though your fluid total would look fine.
Does caffeine need limiting?
The NHS advises drinking caffeine in moderation and checking labels on high-caffeine drinks. For pregnancy it gives a clear limit: no more than 200mg of caffeine a day, as higher intakes could increase the risk of miscarriage or low birth weight. If you are pregnant, check the caffeine content of tea, coffee, cola and energy drinks, and ask your midwife or GP if you are unsure.
For most other adults the practical point is the same as with sugar: tea and coffee can be part of your fluids, but they work best alongside plain water rather than instead of it, and not as the only source late into the evening if your sleep is suffering.
Who is more likely to become dehydrated?
The NHS lists babies, children and older adults as being at higher risk of dehydration. It also names other risk factors, including:
- diabetes
- sickness or diarrhoea
- prolonged time in the sun or heat
- heavy alcohol use
- heavy sweating from exercise
- a high temperature
- taking diuretic medicines
- depending on other people for drinks
If you look after someone who falls into any of these groups, the NHS suggests encouraging drinks at mealtimes, making drinking a social activity, offering foods with a high water content such as soup, jelly and melon, and keeping drinks within easy reach. These small environmental changes often matter more than reminders.
If you take a diuretic medicine, do not change how much you take or stop it because of anything in this article; speak to your pharmacist or prescriber if you are unsure about fluids.
How can you make drinking a habit?
For most people the difficulty is not knowing the guidance but remembering to follow it, especially when busy. Tying a drink to something you already do is the approach that tends to work best, which is the same principle described in our article on building a habit that sticks.
Some ideas that fit a London day:
- Have a glass of water when you first get up, alongside the kettle going on.
- Keep a refillable bottle or glass at your desk, or on the table beside you if you work from home.
- Pair a drink with a regular cue, such as every time you sit down on the Tube or finish a meeting.
- Order water with lunch rather than a sugary drink.
- If plain water is dull, try diluted sugar-free squash or a slice of lemon in a glass.
Tap water is a perfectly reasonable choice, and carrying a refillable bottle also gives you a reason to get up and move during the working day.
When should you speak to a GP or NHS 111?
Most mild dehydration can be treated by drinking fluids, taking small sips if you feel sick and gradually increasing them. The NHS advises avoiding caffeinated drinks and alcohol while you are dehydrated. If you are losing fluid through sickness or diarrhoea, a pharmacist can recommend oral rehydration solutions.
The NHS advises getting an urgent GP appointment or calling NHS 111 if you have:
- unusual tiredness or drowsiness
- dizziness when standing that does not pass
- dark urine, or you are peeing less than normal
- a fast heart rate or fast breathing
- few or no tears (in a child), or a sunken soft spot on a baby’s head
For a child under 5, the NHS says to call 111 for advice. Call 999 or go to A&E if there is blue, grey, pale or blotchy skin, lips or tongue, cold skin, difficulty breathing, confusion, or excessive sleepiness or difficulty waking, as these can be signs of shock. Do not drive yourself, and bring any medicines you take.
A steady habit, not a daily scorecard
The NHS message on fluids is refreshingly modest: roughly 6 to 8 cups or glasses a day, with tea, coffee, milk and water all counting, pale yellow pee as a quick check, and more when it is hot, when you are active or when you are unwell. Keeping juice to a small glass, going easy on sugary drinks and watching caffeine in pregnancy covers most of the rest. For a healthy adult, that is enough; if something feels persistently off, or you are caring for someone vulnerable, ask for advice rather than guessing. A broader look at what goes on the plate alongside the glass is in our guide to a balanced everyday diet.
This article is general information, not a substitute for advice from a doctor or other qualified health professional. If you are worried about dehydration or your health, speak to your GP or call NHS 111.
Sources: NHS
