HydrationFebruary 22, 2026 6 min read
How Much Water Should You Really Drink?
The eight-glasses rule is a myth. Here is what actually determines your hydration needs — and how your body tells you when you're behind.
There is no universal number of glasses. Your needs shift with body size, climate, diet and activity — which is exactly why measuring your own hydration beats following a rule.
Why one number can't fit everyone
A large, active person in a hot climate needs far more fluid than a small, sedentary one in a cool room. Food, caffeine and alcohol all move the equation too.
0
universal number
4
factors that shift needs
Urine
as the guide
Adaptive
targets
Let your body set the target
Urine colour and concentration reveal whether you are meeting your true needs. Trending them replaces a rigid rule with a personal, adaptive target.
- Body size and composition
- Climate and temperature
- Activity level
- Diet, caffeine and alcohol
“Your own urine trend is a better guide than any fixed number.”
Practical rhythm
Sip through the day, drink more around activity and heat, and use the trend as your feedback loop.
