Water carry calculator

Longer distances mean more time on the trail and more physical exertion. Your body loses water through perspiration, breathing, and metabolic processes.

Your hiking pace determines how long you'll be on the trail. Faster paces mean shorter trips but higher exertion. Typical hiking pace is 4km/h (2.5mph) on flat terrain, slower with elevation gain or heavy pack.

Climbing requires significantly more energy and oxygen. Every 300m (1,000ft) of elevation gain roughly equals 1km of flat distance in effort. Higher altitudes also increase respiratory water loss due to lower humidity and increased breathing rate.

Higher temperatures dramatically increase sweat production to cool your body. At 85°F+, you can lose 2x more water than at moderate temperatures. Cold weather also requires hydration, though less so.

UV radiation heats your skin and increases core body temperature, causing you to sweat more to maintain cooling. Higher UV also means more direct sun exposure, compounding heat effects. UV increases ~10-12% per 1,000 meters elevation.

Breathing through your mouth during exercise increases water loss through respiration by about 15%. Mouth breathing bypasses the nasal passages which normally humidify exhaled air, leading to more moisture loss with each breath.

Some people naturally sweat more due to genetics, fitness level, or higher sweat gland density. Heavy sweaters can lose 20-30% more fluid during exercise compared to average, requiring additional water intake to maintain proper hydration and performance.