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Daily Water Intake Calculator
Calculate recommended daily water intake based on weight and activity
Nutrition
kg
What This Calculator Measures
This calculator estimates your optimal daily water intake based on body weight and activity level. Proper hydration is critical for training performance, recovery, and overall health. Even mild dehydration (2% of body weight) can reduce strength output by up to 10%.
How It Works
**Base intake = Body Weight (kg) x 0.033 liters**
This base is then adjusted by an activity multiplier:
| Activity Level | Multiplier | Example (80 kg) |
|---|---|---|
| Sedentary | 1.0x | 2.6 L |
| Moderate | 1.2x | 3.2 L |
| Active | 1.4x | 3.7 L |
| Very Active | 1.6x | 4.2 L |
Hydration Tips for Lifters
•Drink 500 ml of water 1-2 hours before training.
•During training, aim for 200-300 ml every 15-20 minutes.
•After training, replace 150% of fluid lost through sweat (weigh yourself before and after if precise).
•Electrolytes (sodium, potassium, magnesium) matter as much as water volume for those training intensely or in hot conditions.
Limitations
•Climate and temperature significantly affect hydration needs. Hot or humid environments require substantially more water.
•These are estimates. The best hydration indicator is urine color: pale yellow indicates adequate hydration.
•Individual sweat rates vary enormously. Some people lose 1+ liters per hour during intense exercise.
•Coffee and tea count toward water intake despite the mild diuretic effect.
Frequently Asked Questions
- How much water should I drink per day if I lift weights?
- A good baseline is half your bodyweight in ounces, plus 16-20 oz for every hour of exercise. A 180 lb guy training for an hour should aim for roughly 110 oz (about 3.3 liters). More if you sweat heavily or live in a hot climate.
- Does dehydration actually affect my strength?
- Yes. Even 2% dehydration can reduce strength output by 10-20% and tank your endurance. If you feel weak in the gym for no reason, check your water intake first. It's the simplest performance variable most guys ignore.
- Should I drink water during my workout?
- Sip water throughout your session -- don't wait until you're thirsty. Aim for 7-10 oz every 10-20 minutes during intense training. Chugging a huge amount at once can cause cramping. Steady sips beat big gulps.
- Do coffee and other drinks count toward my water intake?
- Mostly, yes. Coffee, tea, and other beverages contribute to hydration despite mild caffeine effects. But plain water should still be your primary source. Don't count alcohol -- it's a net dehydrator.