💧 Daily Water Intake Calculator

Your Body Weight

For most adults, between 20-225 kg (44-500 lb)

Activity Level Daily Climate

What does this calculator do?

The Daily Water Intake Calculator gives you a personalized recommendation for how much water you should drink each day, based on your weight, activity level, and the current climate. Staying hydrated is crucial for overall health and wellness—this tool helps you estimate your daily intake for optimal hydration.

How to use the calculator

Enter your body weight and select the correct unit (kg or lb).
Choose your typical activity level.
Select your daily climate setting.
Press Calculate to see your recommended daily water intake.
Try the Sample button to see a realistic worked example.
Use Reset to clear inputs and start again.

Worked example

Example: For a 70 kg (154 lb) adult, moderately active, living in a temperate climate:
Result: About 2.58 liters (87 oz) per day.
(Based on standard health and fitness guidelines; see Assumptions below.)

Assumptions & calculation method

Base Calculation: 35 ml per kg of body weight (2/3 ounces per pound). For example, 70 kg x 35 = 2,450 ml.
Activity Level:
- Sedentary: Base amount.
- Moderate: +12% of base.
- Active: +22% of base.
Climate Adjustment:
- Hot/humid: +10% of subtotal.
- Cold: -5% of subtotal.
- Temperate: No change.
The tool provides healthy estimates only for general fitness and information. For specific health conditions or intense athletics, consult a professional.

FAQ: Water Intake Guidance

Is it possible to drink too much water?: Yes. Drinking excessive amounts in a short period can be unsafe. Follow recommended values and listen to thirst cues.
Does my water intake include tea, coffee, or foods?: Yes, but tool results are for total fluids from water plus beverages and moderate food moisture. High-caffeine drinks may have less hydrating effect.
Should children use this calculator?: No—children and elderly adults typically have different needs. This calculator is for healthy adults only.