Water Intake Calculator
Find your personalised daily hydration target based on your body and lifestyle
// How We Got There
// Suggested Drinking Schedule
// Hydration Facts
How Your Water Target Is Calculated
There is no single universal hydration formula — needs vary significantly based on body size, activity, climate and health status. This calculator uses a weight-based baseline and adds adjustments for each lifestyle factor.
The Formula
Signs of Dehydration
Mild dehydration: thirst, dark urine, dry mouth, headache, difficulty concentrating. Moderate: dizziness, fatigue, reduced urine output. Severe dehydration requires medical attention — symptoms include rapid heartbeat, sunken eyes, and confusion.
Does Coffee Count?
Yes — despite being mildly diuretic, caffeinated drinks like coffee and tea still contribute net fluid to your hydration. The water they contain more than compensates for the diuretic effect in moderate quantities. Alcohol is a stronger diuretic and does not count positively toward hydration goals.
Hydration and Weight Loss
Drinking water before meals can reduce calorie intake. Water is also essential for metabolising stored fat. Some studies suggest that mild dehydration can be mistaken for hunger. Adequate hydration supports both energy levels and exercise performance.
// Morning First
Drink a large glass of water immediately on waking — you lose about 500ml overnight through breathing and sweating.
// Urine Check
Pale straw yellow = well hydrated. Clear = possibly over-hydrated. Dark yellow = drink more immediately.
// Don't Wait for Thirst
Thirst is a late signal of dehydration. By the time you feel thirsty, performance may already be affected.
// Food Counts
Fruits and vegetables provide up to 20% of daily water needs. Cucumber, lettuce and watermelon are over 90% water.