Daily Water Intake Calculator
How much water you should drink based on weight, activity, and climate
Enter Details
kg
Results
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Enter your details and click Calculate.
Formula
Base = weight (kg) × 0.033 litres Adjusted for activity and climate
- weight (kg) — Body weight
- activity add-on (L) — +0.5 L moderate, +1.0 L intense exercise
- climate add-on (L) — +0.3 L hot/humid weather
Example: 70 kg, moderate exercise, temperate: 70 × 0.033 + 0.5 ≈ 2.8 L/day
Interpreting Your Result
< 1.5 L
Inadequate
Risk of dehydration
1.5–2.0 L
Minimum
Sufficient at rest only
2.0–3.5 L
Adequate
Recommended for most adults
> 3.5 L
High need
Appropriate for athletes or hot climates
Frequently Asked Questions
Does coffee count toward water intake?
Moderate coffee and tea does contribute despite mild diuretic effects. Plain water is still ideal.
What are signs of dehydration?
Dark urine, headache, fatigue, and poor concentration. Thirst is often a late indicator.