Find your daily water intake target based on weight, activity level and climate.
The 'drink 8 glasses a day' rule is one of those health myths that won't die — it has no scientific basis and doesn't account for the fact that water needs vary enormously based on body size, activity, climate, and diet. Your actual requirement is more personal than that.
This calculator estimates your daily water intake based on your weight and activity level. It's a starting point — not a rigid prescription. Much of our daily fluid intake also comes from food, particularly fruit, vegetables, and other beverages.
Signs you're not drinking enough include dark yellow urine, headaches, fatigue, and reduced concentration. If you're exercising hard in Queensland summer heat, your needs will be significantly higher than the baseline estimate.
Yes, despite the common myth. While caffeine has a mild diuretic effect, the fluid in coffee and tea still contributes positively to your daily total. Very high caffeine intake (6+ cups) may shift this, but moderate coffee consumption counts.
Yes — significantly more. A general guide is to drink an extra 500-750ml for every hour of moderate exercise, more in hot conditions or for intense activity. Weighing yourself before and after exercise can help you calibrate: 1kg of weight lost equals roughly 1 litre of fluid deficit.
Yes, though it's rare in everyday life. Hyponatremia (dangerously low sodium from excessive water intake) is mainly a risk for endurance athletes who drink large amounts of plain water without electrolyte replacement during prolonged exercise. For most people, thirst is a reliable guide.
Yes — Australian tap water is treated and regulated to high standards in all major cities and towns. It's among the safest drinking water in the world and perfectly fine for meeting your daily intake.