Free Daily Water Intake Calculator & Hydration Tools
Calculate your daily water goal, track progress, create a schedule, export professional PDF trackers, and find the right bottle — all free, offline, no login needed.
💧 Daily Water Intake Calculator
All 15 Hydration Tools
Water Intake by Weight
Low/medium/high daily water range
Water Intake — KG
Metric weight → litres, cups, bottles
Water Intake — LBS
Imperial weight → oz, cups, litres
Bottle Count Calculator
How many bottles per day?
Drinking Schedule
Personalised water-drinking timetable
Water Reminder Timer
Countdown with sound & notifications
Daily Water Tracker
Log intake in real time, saved locally
7-Day Challenge
Progressive 7-day hydration plan
Printable PDF Tracker
Professional PDF export — daily/weekly/monthly
Workout Hydration
Before, during & after exercise water
Hot Weather Calculator
Extra water in heat & humidity
Kids Water Calculator
Age-appropriate estimates for children
Progress Chart
Circular visual progress & motivation
Bottle Size Recommender
Smart pick for your lifestyle & goal
⚖️ Water Intake by Weight Calculator
Get a personalised daily water range based on body weight and activity.
🔢 Water Intake — KG Calculator
Metric weight input. Results in litres, ml, cups and bottles.
🇺🇸 Water Intake — LBS Calculator
Imperial weight input. Results in oz, cups, litres and bottles.
🧮 Water Bottle Count Calculator
Enter your daily goal and bottle size to calculate how many bottles you need.
📅 Daily Water Schedule Generator
Creates a personalised drink-by-time timetable for your day.
⏰ Water Reminder Timer
Countdown timer with sound and browser notification reminders.
📊 Daily Water Tracker
Log your intake. Data saved in your browser — auto-resets each new day.
🏆 7-Day Hydration Challenge Generator
Build up to your target intake progressively over one week.
🖨️ Professional Printable Water Tracker
📄 Tracker Settings
👤 Personal Details
🎨 Colour Theme
Click a colour to select. Hover for name.
🔧 Layout Options
➕ Include Sections
📅 Schedule (if enabled)
💪 Workout Hydration Calculator
🌞 Hot Weather Water Calculator
Extra water needed when spending time outdoors in heat.
👶 Kids Water Intake Calculator
📈 Hydration Goal Progress Chart
Visualise how close you are to your daily goal.
🍶 Smart Bottle Size Recommender
Find the ideal bottle size for your lifestyle, goal and habits.
Understanding Daily Water Intake
How Much Water Should I Drink Daily?
The standard guideline is approximately 35 ml per kg of body weight. A 70 kg adult needs roughly 2.45 litres per day, but this varies with activity, climate, age and health status.
How This Calculator Works
Base: 35 ml/kg. Activity: Low +0 ml, Normal +250 ml, Active +500 ml, Very Active +750 ml. Climate: Hot +400 ml, Very Hot +700 ml.
⚠️ Medical Disclaimer
All results are educational estimates only and are NOT medical advice. People with kidney disease, heart conditions, pregnancy or other health concerns must consult a qualified healthcare professional before changing fluid intake.
Frequently Asked Questions
How much water should I drink daily?
A general rule is 35 ml per kg of body weight. A 70 kg adult needs around 2.45 litres. Use our calculator for a personalised estimate based on your weight, activity and climate.
Is this water intake calculator medical advice?
No. All calculations are for educational purposes only. Always consult a healthcare professional, especially if you have medical conditions.
Does body weight affect water intake?
Yes. Weight is the primary factor. Larger bodies have more cells requiring hydration and lose more fluid through skin and breathing.
How much water is too much?
Drinking more than 3–4 litres per hour can cause hyponatremia. Healthy adults rarely need more than 3–4 litres per day unless very active in heat.
How many bottles of water should I drink per day?
Divide your daily goal by your bottle size. For a 2 L goal with a 500 ml bottle, you need 4 bottles. Use our Bottle Count Calculator for exact results.
Does the tracker save my data?
Yes. Data is saved in your browser's localStorage. It never leaves your device and resets automatically at the start of each new day.
Can I print a water tracker?
Yes. Use our Professional Printable Tracker to generate daily, weekly or monthly sheets with 10 colour themes and multiple export options including PDF.
Should I drink more water when exercising?
Yes. Exercise increases fluid loss through sweat. Use our Workout Hydration Calculator to estimate how much extra water you need.
Should I drink more water in hot weather?
Absolutely. Use our Hot Weather Calculator. Spending 4 hours outdoors at 35°C can require an extra 400–600 ml depending on your activity.
Is this suitable for kids?
We have a dedicated Kids Water Intake Calculator with age-appropriate estimates. Always consult your paediatrician for personalised advice.
What bottle size is best?
Use our Smart Bottle Size Recommender. Generally: 500 ml for office and school, 750 ml for gym, 1 L for outdoor activities.
Why does climate affect hydration?
In hot or humid conditions your body sweats more to regulate temperature, increasing fluid loss and raising your daily water requirement significantly.
Can I drink too much water?
Yes. Drinking very large amounts in a short time can dilute blood sodium and cause a rare but serious condition called hyponatremia. For most healthy adults this is uncommon, but endurance athletes should be cautious. See the Mayo Clinic water guidance for details.
Does caffeine affect hydration?
Moderate caffeine from coffee or tea has only a mild diuretic effect and still contributes to your daily fluid intake. Very high doses may slightly increase fluid loss, so balance caffeinated drinks with plain water.
Mineral water vs. tap water — which is better for hydration?
Both hydrate equally well. Mineral water adds small amounts of minerals like calcium and magnesium, while safe tap water is convenient and low cost. The World Health Organization publishes drinking-water guidelines on safe water quality.
Is this calculator suitable for athletes?
It gives a useful baseline, but athletes lose extra fluid and electrolytes through sweat. Use our Workout Hydration Calculator for exercise needs and consider a sports professional for intense training or competition.
How does pregnancy affect water intake?
Pregnancy and breastfeeding increase fluid needs to support blood volume and milk production. Requirements are higher than the standard estimate, so pregnant and nursing people should follow advice from their healthcare provider.
Should I drink more water in extreme heat?
Yes. Heat waves sharply raise the risk of dehydration and heat illness. Drink before you feel thirsty and stay in shade or cool areas. The CDC heat-health resources cover heat-related illness prevention.
🔒 Privacy & Data
✅ No account required | ✅ All data stays on your device | ✅ Tracker uses localStorage only | ✅ No data is transmitted | ✅ Clear browser data to erase all saved progress.