Calculate your personalized daily water intake goal based on your body weight, activity level, and climate. This calculator helps you understand how much water you really need during the 75 Medium Challenge—and how it compares to 75 Hard's strict gallon requirement.
Calculate Your Daily Water Goal
Your Personalized Water Goal
Daily Goal
--
fluid ounces
Daily Goal
--
liters
Glasses (8oz)
--
per day
--%
of 1 gallon
⚖️ Compared to 75 Hard's Gallon Requirement
0 oz
Your goal
128 oz (1 gal)
How This Calculator Works
This calculator uses a science-based formula that considers three key factors:
- Body Weight: Your baseline water needs scale with body mass. The formula uses approximately 0.5-1 oz per pound of body weight.
- Activity Level: Exercise increases water loss through sweat. More active individuals need 20-80% more water.
- Climate: Hot and humid environments increase perspiration, requiring 10-20% more hydration.
🧘 75 Medium Flexibility
Unlike 75 Hard's mandatory gallon (128 oz) for everyone, 75 Medium encourages adequate hydration based on your individual needs. Use this calculator to find your optimal intake, and adjust based on how you feel.
Hydration Tips for Success
💧
Start early: Drink 16-20 oz of water
within 30 minutes of waking up to rehydrate after sleep.
⏰
Set reminders: Use your phone or a water
tracking app to remind you every 1-2 hours.
🕐
Pre and post workout: Drink 16-24 oz
before exercise and replenish with 16-24 oz afterward.
💧
Add flavor: If plain water is boring,
add lemon, cucumber, or mint for natural flavor.
💧
Keep water visible: Always have a water
bottle at your desk, in your car, and by your bed.