Daily Hydration Calculator
Estimate your personalized daily hydration goal based on your weight, activity, and climate, and track your daily water intake with the built-in tracker.
This hydration guide is for educational reference. It is not medical advice, diagnosis, or prescription. Consult a professional for health conditions or specific hydration needs.
Hydration Guide
2.7 L
2,700 mL
0 L
0 mL
0%
2,700 mL
Hydration Status
Start drinking water
Log your water intake to achieve today's hydration goal.
Hydration Status
Basics & Environment
Enter weight and select usual activity and climate to calculate your water goal.
Water Tracker
Log your water intake to achieve today's hydration goal.
Water Logs
오늘 기록된 수분 공급 목록입니다.
No water logged today. Log a cup of water below to start tracking!
Water Estimate and Fluid-Restriction Cautions
Reference date and last reviewed: July 11, 2026
Calculation Basis
Uses this site’s convenience model of 30, 35, or 40 mL/kg by activity plus fixed activity allowances of 0, 250, or 500 mL and climate allowances of 0, 350, or 700 mL.
Reference Limits
It is not an official individualized prescription and does not measure food and beverage water, sweat rate, workout duration, pregnancy, breastfeeding, fever, diarrhea, medication, or electrolyte loss.
When to Confirm Officially
With kidney, heart, or liver disease, diuretics, hyponatremia risk, or prescribed fluid restriction, do not follow the estimate; confirm an appropriate amount with the treating clinician.
Usage Tips
Adjust your water goal for activity level and weather
Daily water intake can change not only by body weight, but also by exercise, time spent outdoors, hot weather, and humidity. Calculate your water goal with your usual activity level and current environment in mind, then track the remaining amount throughout the day instead of drinking it all at once.
What is Daily Hydration Calculator?
The Daily Water Intake Calculator estimates a personalized hydration goal from body weight, activity level, and climate. It also works as a simple water tracker, showing water consumed, progress percentage, and the amount remaining. A fixed eight-glass or two-liter rule does not fit everyone: fluid needs vary with body size, food, exercise, sweat rate, weather, pregnancy or breastfeeding, medication, and health conditions. Use the result as a practical lifestyle reference rather than a medical prescription.
How to Use
- 1Enter your body weight and choose kilograms or pounds; pounds are converted internally for the calculation.
- 2Select low, moderate, or high activity based on your usual movement, exercise, and sweating.
- 3Choose normal, hot, or very hot and humid conditions to account for environmental fluid loss.
- 4Review the estimated daily water goal, weight-based amount, activity allowance, and climate allowance.
- 5Select a cup size or enter a custom milliliter amount whenever you drink water.
- 6Use the water tracker to monitor progress and remaining intake, then reset the log when starting a new period.
Water target by weight, activity, and climate
Last reviewed: July 11, 2026This tool’s hydration estimate
daily water target = weight kg×30/35/40 mL + activity extra + climate extra
The site adds activity allowances of 0, 250, or 500 mL and climate allowances of 0, 350, or 700 mL to a weight-based amount. This is a convenience model, not an official individualized medical prescription.
Example: 70 kg, moderate activity, hot climate
- • Weight: 70 kg
- • Moderate activity: 35 mL/kg + 250 mL
- • Hot climate: +350 mL
- 1. base: 70×35 = 2,450 mL
- 2. activity and climate extras: 250+350 = 600 mL
- 3. total: 2,450+600 = 3,050 mL
This tool displays a daily water target of 3,050 mL, or about 3.05 L.
How to read the result
- Interpret the total as fluid from foods and beverages, not only plain bottled water.
- Changing activity or climate can alter both the weight-based rate and a fixed allowance.
- Use thirst, urine color, weight change, and observed sweat loss as additional context.
Conditions that change the result
- The model does not directly enter sweat rate, workout duration, pregnancy, breastfeeding, fever, diarrhea, or electrolyte loss.
- Do not follow the estimate when kidney, heart, or liver disease, diuretics, or a prescribed fluid restriction applies.
- Excess water can also be harmful, so do not consume the whole target at once.
Common input mistakes
- Entering pounds while kilograms are selected makes the target about 2.2 times too high.
- Avoid double-counting all food and beverage water after treating the result as a plain-water requirement.
- Do not select a higher activity or climate level than actual conditions just to raise the goal.
Reference Knowledge
- ●The calculator applies approximately 30, 35, or 40mL per kilogram according to activity level.
- ●Higher activity and hotter conditions add estimated allowances for increased sweat and respiratory fluid loss.
- ●Daily fluid intake includes water from food, milk, tea, coffee, soups, fruit, and other beverages.
- ●A daily water goal is not the same as a requirement to drink that entire amount as plain bottled water.
- ●Exercise duration, sweat rate, humidity, pregnancy, breastfeeding, medication, and illness can substantially change individual needs.
- ●Spreading fluids throughout the day is generally more practical than consuming a very large amount at once.
- ●Prolonged strenuous exercise may require attention to electrolytes as well as water.
- ●Urine color and thirst are useful clues but cannot diagnose dehydration on their own.
- ●Anyone with a prescribed fluid restriction should follow professional medical guidance instead of this estimate.
FAQ
Q.How much water should I drink each day?
Needs vary by body size, activity, climate, diet, and health. This daily water intake calculator provides a personalized general reference rather than one universal target.
Q.Do I need exactly eight glasses or two liters of water?
No single amount fits everyone. Body weight, activity, food, weather, and health can make an appropriate daily water goal higher or lower.
Q.How is water intake by weight calculated?
The calculator multiplies weight in kilograms by an activity-based rate of about 30 to 40mL, then adds allowances for activity and climate.
Q.Do coffee and tea count toward hydration?
Most beverages and water-rich foods contribute to total fluid intake, although relying mainly on sugary or highly caffeinated drinks is not ideal.
Q.Should I drink more water when exercising?
Longer exercise, higher intensity, and greater sweating can increase fluid needs. Electrolytes may also matter during prolonged strenuous activity.
Q.Can I drink the whole target at once?
It is generally better to spread intake across the day instead of consuming a very large amount in a short period.
Q.Can urine color show hydration status?
Urine color can be a useful clue but is also affected by food, medication, and supplements, so it is not a diagnosis by itself.
Q.Does hot weather increase my water goal?
Hot and humid weather can increase sweating. Selecting the matching climate setting adds an estimated allowance to the daily goal.
Q.Does food count toward daily fluid intake?
Yes. Fruit, vegetables, soups, dairy products, and many other foods contain water and contribute to total hydration.
Q.Is this result medical advice?
No. It is a general estimate, not a dehydration diagnosis or personal prescription. Follow qualified medical guidance when health conditions or fluid restrictions apply.
