Hydration Calculator

CamelBak helps you determine your ideal level of hydration

How much water should you drink?

Determine how much water you need for maximum performance.


    The CamelBak Hydration Calculator was built in cooperation with the University of Connecticut’s Korey Stringer Institute (KSI). The calculator is designed to educate you about the different factors that influence dehydration requirements during activity. It is meant to give you a general indication of your sweat losses during activity, and should not take the place of specific individual needs, medical advice or common sense. If the conditions of your activity change, you should reassess your hydration strategy accordingly.

    For a more precise understanding of your hydration requirements during physical activity, follow the steps outlined in KSI’s Sweat Rate Calculation Worksheet.

    Consult your doctor before starting a new diet or exercise routine.

  • Tell us about yourself



    Height combined with Weight provides us with your Body Mass Index or BMI. BMI is used in our calculation to factor in the surface area of your skin. The more surface area you have the greater amount of sweat you produce.

    Formula: weight / [height]2


    Weight combined with Height provides us with your Body Mass Index or BMI. BMI is used in our calculation to factor in the surface area of your skin. The more surface area you have the greater amount of sweat you produce.

    Formula: weight / [height]2


    Interestingly, age does affect how the human body uses water. For example, as people age, their kidney is not able to conserve water as well. Also, their thirst sensation tends to lessen, making them more susceptible to dehydration.

    • Gender

    • Height

      {{height | feetinches}}
    • Weight

      {{weight}} LBS
    • Age

  • What's your current hydration level??

    What color is your urine?

    The best way to assess your current hydration level is urine color. Your selection here tells us whether or not you are beginning your activity with a water deficit. To maintain healthy hydration levels throughout the day, regulate water intake so that you excrete urine that is the color of lemonade – not apple juice.

    HydratED Video: easy tips for staying hydrated throughout the day.

    How Much Do You Typically Sweat

    Light: Small amounts of sweat appear on your forehead.
    Moderate: Large amounts of sweat on your forehead, neck and armpits.
    Heavy: Your head drips with sweat. Your shirt frequently becomes saturated in armpits and chest areas. Salt deposits may also accumulate in those zones.

    Sweat is by far the most efficient way your body has to cool itself. Your body will sweat in response to internal overheating regardless of the temperature outside. Through sweat you lose about 1-liter of water per hour during moderate activity. How much you typically sweat is a key factor in determining how much water you need to drink during your activity to replenish the loss of fluid.

    Learn how to calculate your sweat rate.

    • What color is your urine?

    • How Much Do You Typically Sweat

      Light Moderate Heavy
  • Describe your activity


    Each activity exerts different demands on the body and can affect sweat levels. We have included a basic selection of sports that encompass high-aerobic to anaerobic activities. If your chosen sport or exercise is not listed here, simply choose the activity that most closely mirrors yours as far as physical demand.

    Activities can dictate the type of apparel you wear and the type of gear you may be carrying. Typically, clothing adds insulation and increases your sweat rate. The addition of backpacks to Hikers increases the energy costs of locomotion and reduces the surface area available for heat transfer, thereby further increasing dependence on sweating to cool the body. Sports in which protective equipment is worn (eg, football) should ensure that frequent hydration breaks are implemented into a practice session since this type of equipment has also been shown to affect heat dissipation from the body during exercise.

    Read more at HydratED.


    Time and Intensity are two of the largest factors in determining how much water you should drink during your exercise or race. Obviously, the longer you are out there, the greater your total water requirement.


    More than any other factor, intensity will significantly influence your hydration requirements. Are you running close to top speed flat out for 30 minutes? Or are you running closer to a jogger’s pace for 30 minutes? The difference in sweat rate and therefore hydration demands could be significant.

    It’s important to honestly assess your intensity as this is a critical factor in your overall hydration needs. As your intensity increases, you sweat more, and therefore dehydrate at a faster rate. To sustain a high-intense workout for a longer period of time it’s important to understand your target water consumption and drink consistently throughout the session to keep your body’s hydration level in balance. This will keep your muscles functioning properly to reach optimal endurance levels.

    Learn more about how your body uses water.

    • Activity

    • Time

      {{time | hoursminutes}}
    • Intensity

        • LOW
        • MEDIUM
        • HARD
        • INTENSE
      • {{intensity | intensityLabel}}
  • Weather

    Although relative humidity has little impact on sweating and water requirements in temperate environments, high humidity conditions in hot tropical environments can increase water requirements as much as 2-fold.


    Intense workouts in heat have a role in both dehydration rates and cognitive function such as hand-eye coordination and concentration. Dehydration rates in the heat have a smaller safety net than an activity performed in 40-degree weather.

    Dehydration increases exercising core body temperature, and when exercising in the heat, dehydration will lead to a greater core body temperature than when hydrated. Exercise in the heat has the potential to limit exercise performance due to the cardiovascular, thermoregulatory, metabolic, and neuromuscular changes that occur in the body.

    What are the weather conditions

    • Choose weather

    • /


Get a more detailed recommendation at Hyrdated Logo

Hydration Calculator

How much water should you be drinking

See How Much

Ditch The Disposable

Help rid the world of disposable bottles

Take The Pledge


Drinking water is vital to performance

Learn More