Water is essential for everyday life, but many people are unsure how much water they should drink each day.
Your daily water needs can vary depending on your body size, activity level, climate, diet, and other factors.
A Water Intake Calculator can give you a simple estimate of how much water you may need each day.
What Is Daily Water Intake?
Daily water intake is the total amount of water your body receives throughout the day.
This includes water from:
- Drinking water
- Other beverages
- Foods that contain water
Fruits, vegetables, soups, milk, and many other foods and drinks can contribute to your total daily fluid intake.
How Much Water Do You Need?
There isn’t one exact amount that works for everyone.
One simple estimation method sometimes used is based on body weight:
Daily Water (mL) = Body Weight (kg) × 30–35 mL
For example, suppose someone weighs 70 kg.
Using 30 mL per kilogram:
70 × 30 = 2,100 mL
Using 35 mL per kilogram:
70 × 35 = 2,450 mL
That gives an estimated range of approximately:
2.1–2.45 liters per day
This is only a general estimate, not an individual medical recommendation.
Example 1 — 60 kg
Suppose your body weight is 60 kg.
Using 30 mL per kilogram:
60 × 30 = 1,800 mL
Using 35 mL:
60 × 35 = 2,100 mL
Estimated range:
1.8–2.1 liters per day
Example 2 — 80 kg
Suppose your body weight is 80 kg.
Using the same simple method:
80 × 30 = 2,400 mL
80 × 35 = 2,800 mL
Estimated range:
2.4–2.8 liters per day
Quick Water Intake Examples
| Body Weight | 30 mL/kg | 35 mL/kg |
|---|---|---|
| 50 kg | 1.50 L | 1.75 L |
| 60 kg | 1.80 L | 2.10 L |
| 70 kg | 2.10 L | 2.45 L |
| 80 kg | 2.40 L | 2.80 L |
| 90 kg | 2.70 L | 3.15 L |
These figures are simple estimates. Your actual needs may be different.
What Can Affect Your Water Needs?
Your daily fluid requirements can change depending on several factors.
Exercise: Physical activity and sweating can increase fluid needs.
Weather: Hot or humid conditions may cause you to lose more water through sweating.
Diet: Foods with high water content contribute to hydration, while your overall diet can influence fluid needs.
Pregnancy and breastfeeding: Fluid requirements can change during these periods.
Health conditions: Certain medical conditions and medications can affect how much fluid is appropriate.
For more information about water, hydration, and daily fluid needs, see the CDC’s About Water and Healthier Drinks guide.
For more information about daily water intake and hydration, see the CDC’s About Water and Healthier Drinks guide.
Why Use a Water Intake Calculator?
Doing the calculation manually is simple, but a Water Intake Calculator makes the process faster.
Enter the information requested by the calculator to get an estimated daily water target.
It can be useful for:
💧 Keeping track of daily hydration
🏃 Exercise and active lifestyles
☀️ Hot-weather routines
🥗 Healthy lifestyle planning
📊 Setting a simple daily hydration goal
Factors That Can Affect Daily Water Needs
Daily water needs are not the same for everyone. Your activity level, climate, diet, body size, age, pregnancy or breastfeeding, and certain health conditions can influence how much fluid you need.
Physical activity can increase fluid needs because the body loses water through sweat. Hot or humid weather may also increase fluid loss, especially when you spend time outdoors or exercise.
Food contributes to hydration too. Fruits, vegetables, soups, and other water-rich foods provide some of the fluid your body receives each day. Beverages also contribute to total fluid intake.
A Water Intake Calculator can provide a useful general estimate, but individual needs can vary. People with medical conditions or specific fluid restrictions should follow advice from an appropriate healthcare professional rather than relying only on a general estimate.
Calculate Your Daily Water Intake
Use our Water Intake Calculator to quickly estimate your daily water needs.