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, with no login needed.
ℹ️ Educational estimates only — not medical advice. Consult a qualified healthcare professional for personal guidance, especially for children, pregnancy, breastfeeding, kidney or heart conditions, fluid restrictions, or medicines that affect hydration.
How to use these tools (optional tutorial)
💧 Daily Water Intake Calculator
⚠️ Educational tool — not medical advice
All results are general estimates for healthy adults based on body weight, activity and climate. They are not medical advice and should not replace guidance from a qualified healthcare professional. If you are pregnant or breastfeeding, live with kidney disease, heart failure, diabetes or any condition that affects fluid balance, or take medication that affects hydration, please talk to your doctor before changing how much you drink.
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 Hydration Planning Guide
Broad educational range for parents & guardians
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 in one tap. Your history and streak are saved on this device — nothing is uploaded.
What are you drinking?
Score explanation: An educational comparison — each drink is weighted by an approximate Beverage Hydration Index (still water = 1.0). This is not a measurement of your body\'s hydration and should not be used to diagnose hydration, prescribe intake, or replace water or medical advice. Reference: Maughan et al., Am J Clin Nutr 2016 (PMID 26702122).
📆 Last 30 Days
💾 Backup & Restore
Browsers can clear site data. Export a backup file so a streak is never lost for good.
🏆 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 Hydration Planning Guide
Broad educational range for parents and guardians — not a personalised recommendation.
📈 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?
A widely cited rule of thumb is roughly 35 ml per kg of body weight, so a 70 kg adult might aim for around 2 to 2.5 litres per day. Actual needs vary significantly with activity, climate, diet, age, medication, and individual health, and much of your daily fluid can come from food and other drinks.
How This Calculator Works
Formula: estimated daily drinking-water goal = body weight in kilograms × 35 ml, plus the selected activity and climate adjustments. For example, a 70 kg person starts at 2,450 ml (70 × 35).
Activity adjustment: Low +0 ml; Normal +250 ml; Active +500 ml; Very Active +750 ml. Climate adjustment: Normal +0 ml; Hot +400 ml; Very Hot +700 ml. The result is rounded and shown as litres, glasses and bottles for convenience.
What this result means: it is a general estimate of drinking water, not a measure of all fluid consumed in a day. Food, milk, tea, coffee and other drinks can contribute to total fluid intake. Individual needs may be higher or lower because of health, medicines, sweat rate, diet, age and local conditions.
Rationale: 35 ml/kg is a commonly used practical starting point for healthy adults; the additional amounts make the estimate more responsive to physical activity and heat. It is not a clinical prescription or a substitute for medical advice.
Detailed hydration tools
Daily Water Intake Calculator · Daily Water Tracker · Printable Water Tracker · Workout Hydration Calculator · Hot Weather Water Calculator
⚠️ 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. Every calculator, tracker and printable on this site is for general education only and is not medical advice. Please speak with a qualified healthcare professional before making changes to your fluid intake, especially if you have any health condition, are pregnant or breastfeeding, or take medication.
Does body weight affect water intake?
Weight is one of the main factors most guidelines use, because larger bodies generally have more fluid loss through skin, breathing and metabolism. Individual needs still vary with activity, climate, diet and health.
How much water is too much?
Hydration needs vary greatly with food intake, climate, activity, body size, health conditions and medicines. There is no single drinking-water amount that is right for everyone. Seek professional advice if you have a medical condition or have been told to limit fluids.
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. Your log, 30-day history and streak are saved in your browser (IndexedDB) and never leave your device. Note that browsers can clear site data after a period of inactivity — use Export Backup to keep a copy.
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 Kids Hydration Planning Guide that shows a broad educational range for parents and guardians. It is not a personalised recommendation. Always consult a paediatric healthcare professional for individual guidance.
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 | ✅ Calculator inputs and tracker data stay in your browser | ✅ Tracker uses on-device IndexedDB only | ℹ️ Anonymous usage analytics may be collected through Google Analytics where enabled | ✅ Clear browser data to erase saved progress.
What Users Say About Our Tools
Thousands of people use our hydration tools every day to stay healthy and track their water intake.
"This calculator changed how I think about hydration. I never knew I wasn't drinking enough water until I used this tool. Now I'm healthier and more energetic."
"As an athlete, I needed personalized hydration tracking. The workout hydration calculator is exactly what I was looking for. Highly recommended!"
"Finally, a simple hydration tool! The printable tracker PDF is perfect for my family. We all use it now."
"The reminder timer keeps me accountable. I've built a consistent hydration habit thanks to this app. My skin has never looked better!"
"The dark mode is beautifully designed. I use this tool daily and it's become part of my wellness routine. No ads, no tracking. Perfect!"
"My doctor recommended increasing my water intake. This calculator helped me understand exactly how much I need. Easy, accurate, and free!"