Water intake calculator
Choose your sex and glass size to see the national adequate intake of fluids for healthy adults, in litres and in glasses.
Updated 21 October 2026. Sources named on the page.
Key factThe NHMRC adequate intake of fluids for healthy adults is 2.6 litres a day for men and 2.1 litres a day for women, counting all drinks.
- Based on the national adequate intake of fluids for adults
- Shown in litres, millilitres, glasses and US fluid ounces
- All drinks count, not only plain water
- For adults aged 19 and over; nothing you type is saved or sent
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The reference amounts
These are adequate intakes of fluids from drinks for healthy adults: a level thought to cover the needs of most people, not a target for every person on every day.
Adequate intake of fluids, adults 19 and over
| Group | Per day | Glasses of 250 mL |
|---|---|---|
| Men | 2,600 mL (2.6 L) | 10.4 |
| Women | 2,100 mL (2.1 L) | 8.4 |
Common glass sizes for 2,100 mL
| Glass | Glasses |
|---|---|
| 200 mL | 10.5 |
| 250 mL | 8.4 |
| 300 mL | 7 |
| 500 mL bottle | 4.2 |
Sources: National Health and Medical Research Council (NHMRC), Nutrient Reference Values for Australia and New Zealand, water: adequate intake of fluids; 1 US fluid ounce = 29.5735 mL
General information, not medical advice.
How to use the calculator
Choose your sex, enter your age and pick the size of glass you use. The calculator shows the national adequate intake of fluids for healthy adults, in litres and in glasses of the size you chose.
The figure counts all drinks, and food contributes too, so it is a guide to the whole day, not a target to reach with plain water alone.
Reading the result
The amounts, 2.6 litres for men and 2.1 litres for women, are levels thought to cover the needs of most healthy adults. They are not a minimum for every person on every day. You may need more in hot weather or with exercise or illness, and some conditions call for less. Follow a doctor's advice if you have one.
To turn the number into a habit, the water tracker printable gives you a circle to fill for each glass.
Questions
How much water should I drink a day?
The national adequate intake of fluids is 2.6 litres for men and 2.1 litres for women aged 19 and over. That is what you drink: water, milk and other drinks, so you do not need to drink all of it as plain water. Food adds more water on top.
Do tea and coffee count?
Yes. All drinks count towards your fluids. Water is a good everyday choice.
Do I need more in hot weather or when I exercise?
Usually yes. Needs rise with heat, exercise and illness. The calculator gives a general adult figure and cannot account for these.
Who should not use this?
It is for healthy adults aged 19 and over. Pregnancy, breastfeeding, kidney, heart or other medical conditions change fluid needs, so ask a doctor or an accredited practising dietitian.
Is it possible to drink too much?
Yes, drinking a very large amount in a short time can be harmful. Drink to thirst and steadily through the day, and ask a doctor if you are unsure.
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