Altitude Hydration Calculator
Calculate how much extra water you need at high altitude.
Prevent dehydration and altitude sickness with proper hydration.
At high altitude, your body loses water much faster than at sea level. The air is drier, you breathe faster, and your body works harder to acclimatize.
Why altitude increases water needs:
- Lower humidity: Air above 5,000 feet (1,500 m) is significantly drier. You lose more moisture through breathing and skin evaporation.
- Increased respiration: Your body breathes faster and deeper to compensate for lower oxygen, exhaling more water vapor.
- Increased urination: The body produces more urine at altitude as part of acclimatization.
General hydration guidelines by altitude:
- Sea level to 5,000 ft (1,500 m): Normal intake — about 2-3 liters per day
- 5,000-8,000 ft (1,500-2,400 m): Add 0.5-1 liter per day
- 8,000-12,000 ft (2,400-3,600 m): Add 1-1.5 liters per day
- Above 12,000 ft (3,600 m): Add 1.5-2+ liters per day
Activity level matters significantly. Hiking or skiing at altitude can require 4-6 liters per day or more. Even light walking increases needs compared to resting.
Temperature also plays a role. Cold, dry air at altitude causes additional moisture loss. Hot conditions at altitude combine both heat and altitude dehydration effects.
Signs of dehydration at altitude include headache, dizziness, dark urine, and fatigue. These overlap with altitude sickness symptoms, making proper hydration even more important.
Tip: Drink before you feel thirsty. By the time you feel thirst at altitude, you may already be dehydrated.