Altitude

Altitude hydration calculator

Estimate extra water for high altitude, dry mountain air, hiking trips, and ski days.

Altitude and dry air can raise fluid needs because breathing losses increase and sweat evaporates quickly. Add a modest buffer and pace it through the day.

Hours at altitudeAbove roughly 6,000 ft / 1,800 m

hours

Effort / sweatAdjusts the buffer

Already replacedOptional

Bottle sizeFor tracking

Extra fluid estimate

0.9litres

About 30 oz total, or 1.8 bottles over 8 hours.

Pace

125 ml

per hour

Left

0.9 L

1.8 bottles

Electrolytes

Optional

today

When to use electrolytes

Electrolytes are more useful when altitude is paired with hiking, skiing, heat, or low food intake.

Safety note

Severe headache, confusion, shortness of breath at rest, chest symptoms, or worsening altitude sickness symptoms need medical guidance and descent planning.

Sip steadily because thirst can lag behind dry-air losses.

Pair extra water with meals or salty snacks.

Use urine color as one signal, not the only signal.

Frequently asked

Why does altitude increase water needs?

Dry air and faster breathing can increase respiratory fluid loss. Activity at altitude can also hide sweat because it evaporates quickly.

Will water prevent altitude sickness?

No. Hydration helps comfort and performance, but it does not prevent or treat altitude sickness by itself.