How much water should I drink a day?
The national adequate intake of fluids for adults is 2.6 litres a day for men and 2.1 litres for women. That is what you drink in a day: plain water, milk and other drinks. Food adds more water on top.
Updated 21 October 2026. Sources named on the page.
- The reference amounts in litres, glasses and bottles
- What counts towards fluids
- When needs go up
- For healthy adults aged 19 and over
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Your glasses a day
Choose your sex and glass size and see the amount in litres, glasses and fluid ounces.
The amounts in glasses and bottles
Glasses = daily amount in mL divided by glass size in mL, rounded to one decimal place.
Adequate intake of fluids from drinks, adults 19 and over
| Group | Per day | 200 mL glass | 250 mL glass | 300 mL glass | 500 mL bottle |
|---|---|---|---|---|---|
| Men | 2,600 mL | 13 | 10.4 | 8.7 | 5.2 |
| Women | 2,100 mL | 10.5 | 8.4 | 7 | 4.2 |
Sources: National Health and Medical Research Council (NHMRC), Nutrient Reference Values for Australia and New Zealand, water: adequate intake of fluids
Figures and sources checked 21 October 2026. General information, not medical advice.
What counts
The figure counts what you drink: plain water, milk and other drinks such as tea and coffee. Plain water is a good everyday choice but does not have to make up the whole amount. Food adds water too: the same guidance puts total water, from drinks and food together, at 3.4 litres for men and 2.8 litres for women.
When you may need more
Hot weather, exercise, illness and a very dry climate all raise needs. The reference amount is a general adult figure and cannot allow for these.
Listening to your body
For most healthy adults, drinking to thirst and steadily through the day works well. If you are unsure, or you have a kidney, heart or other medical condition, ask a doctor.
Pregnancy and breastfeeding
Needs are different and this guide does not cover them. A doctor or midwife can advise.
Questions
Is it 8 glasses a day?
Eight glasses is a handy rule of thumb. The reference for women is about 8 glasses of 250 mL and for men about 10, counting all drinks, not only plain water.
Does tea or coffee count?
Yes. Drinks in usual amounts count towards your fluids.
Do I need to drink more when I exercise?
Usually yes. Needs rise with exercise and heat. Drink to thirst and keep a drink handy.
Can you drink too much?
Yes. Very large amounts in a short time can be harmful. Drink steadily and ask a doctor if unsure.
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