You hear it everywhere: drink more water. But how much water should you drink a day, really? The honest answer is: it depends. Your body, your lifestyle, your training, the weather outside: they all play a role. This guide cuts through the noise and gives you practical, science-backed guidance on how much water you should drink a day, what happens when you drink too little (or too much), and how to stay properly hydrated whatever your day looks like.
Why Water Is So Important
Water makes up roughly 60% of your body. It is involved in practically every process that keeps you going: regulating body temperature, transporting nutrients, flushing out waste, supporting kidney function, lubricating joints and enabling your muscles to contract properly.
The benefits of staying consistently well hydrated go beyond avoiding thirst. Good hydration supports concentration and mental clarity, keeps your skin healthier, aids digestion and helps your body perform at its best during exercise and recovery. Being fit is the foundation for everything you do, and hydration is one of the most fundamental pillars of that foundation.
How Much Water Should You Drink a Day?
When people ask how many litres of water per day they need, the most commonly cited guideline is around 2 to 2.5 litres for the average adult. This figure comes from general health recommendations and reflects total fluid intake from both drinks and food (roughly 20% of your daily water intake can come from what you eat).
A formula you will often see is based on body weight:
35 ml per kg of body weight per day
So someone weighing 70 kg would aim for around 2.45 litres of fluid per day. That said, this is a useful starting point, not an absolute rule. Many factors influence how much water you should drink a day, and we will cover those below.
| Body weight | Estimated daily intake (35 ml/kg) |
|---|---|
| 55 kg | ~1.9 litres |
| 65 kg | ~2.3 litres |
| 75 kg | ~2.6 litres |
| 85 kg | ~3.0 litres |
| 95 kg | ~3.3 litres |
These are estimates. Use them as a guide and adjust based on the factors below.
Factors That Affect How Much Water You Need
The 35 ml per kg formula gives you a baseline. But how much water you should drink a day in practice shifts depending on several key factors.
Training and physical activity
Exercise increases your need for water significantly. During intense training you can lose 0.5 to 2 litres per hour through sweat, depending on intensity and conditions. On training days, add at least 500 ml to 1 litre on top of your baseline, and more for long or particularly sweaty sessions. Hydrating before, during and after exercise all matter.
Temperature and climate
Hot weather and high humidity make you sweat more, which increases your fluid loss. If you live in a warm climate or are exercising outdoors in summer, you will need to drink more water than the standard guidelines suggest.
Diet
A diet rich in fruits and vegetables naturally contributes to your fluid intake. Foods like cucumber, watermelon, oranges and leafy greens have a high water content. On the flip side, a high intake of sodium or caffeine can increase your fluid needs.
Health and medication
Illness, fever, vomiting and diarrhoea all increase fluid losses and raise your hydration needs. Some medications also affect fluid balance. If you have a specific health condition, always follow the advice of your healthcare provider.
Pregnancy and breastfeeding
Fluid requirements increase during pregnancy and breastfeeding. General guidelines recommend an additional 300 to 700 ml per day in these phases.
Does It Differ Between Men and Women?
Research does suggest a difference, though it is less dramatic than many people assume. The European Food Safety Authority (EFSA) recommends an adequate intake of approximately 2.0 litres per day for women and 2.5 litres per day for men, from drinks alone (not counting water from food).
On average, men tend to have more muscle mass and higher body weight, both of which increase total water requirements. However, individual variation is large. A highly active woman training twice a day will need significantly more water than a sedentary man of the same weight. The key factors, activity level, body weight, climate and health, matter far more than gender alone.
Signs of Dehydration
Even mild dehydration, as little as 1 to 2% of body weight in fluid loss, can affect how you feel and perform. Common signs include:
- Dark or strong-smelling urine
- Thirst (a late-stage signal, not an early warning)
- Headaches and difficulty concentrating
- Fatigue and low energy levels
- Dry mouth and lips
- Muscle cramps during or after exercise
- Dizziness or lightheadedness
A reliable and simple way to monitor your hydration throughout the day: check your urine colour. Pale yellow means you are well hydrated. Dark yellow or amber signals that you need to drink more. If you are interested in understanding water retention and how it relates to hydration, read our dedicated guide.
Can You Drink Too Much Water?
Yes, and it is worth understanding why. How much water is too much depends on how quickly you consume it relative to what your kidneys can process. The kidneys can handle roughly 0.8 to 1 litre of water per hour. Consuming significantly more than this in a short period can dilute sodium levels in your blood, leading to a condition called hyponatraemia.
Symptoms of hyponatraemia include nausea, headaches, confusion, swelling and in severe cases seizures. It is rare in everyday life, but endurance athletes who drink excessive amounts of plain water over long events without replacing electrolytes are at higher risk.
The takeaway: can you drink too much water? Technically, yes, but for most people drinking sensibly throughout the day, it is not a realistic concern. Spreading your intake evenly across the day rather than drinking large amounts at once is the smartest approach.
What Are Electrolytes and Do You Need Them?
If you have ever wondered what are electrolytes and whether you actually need them, here is a clear answer. Electrolytes are minerals, primarily sodium, potassium, magnesium and calcium, that carry an electrical charge and play a critical role in fluid balance, muscle function and nerve signalling.
When you sweat, you do not just lose water. You also lose electrolytes, particularly sodium. If you replace fluid without replacing electrolytes, your body can struggle to retain and use that fluid effectively. This is especially relevant during prolonged or intense exercise, in hot weather, or if you sweat heavily.
For everyday hydration, water is usually sufficient. But on training days, during long runs, cycling sessions or any activity lasting more than 60 to 90 minutes, supporting your fluid intake with electrolytes makes a real difference. Browse our full electrolytes range, from powders to tabs and ready-made drinks, or try our Isotonic Sports Drink, formulated specifically to support rehydration during and after exercise.
Practical Tips to Hit Your Daily Water Intake
Knowing how much water you should drink a day is one thing. Actually getting there consistently is another. A few habits that make a real difference:
- Start your morning with water. Drink a full glass before your first coffee. It kickstarts your intake for the day.
- Keep a bottle with you. Whether at your desk, in your gym bag or in the car, visible water gets drunk. Our 700 ml Body&Fit bottle fits most bag pockets, while the 1 litre version means fewer refills.
- Set checkpoint goals. Aim to finish one bottle by lunchtime and another by early evening. It removes the guesswork.
- Drink around meals. A glass of water before each meal adds roughly 600 ml to your day without thinking about it.
- Add electrolytes on training days. Especially if you sweat heavily or train for longer sessions.
Want more ideas? Read our full guide on how to drink more water every day.
What About Other Drinks?
Coffee, tea, juice and other beverages all contribute to your total fluid intake. Despite the mild diuretic effect of caffeine, research consistently shows that coffee and tea still provide a net positive fluid contribution. That said, plain water and electrolyte drinks remain the most efficient options for hydration.
If you are looking for a functional boost before training, our Fit Energy Drink contributes to your fluid intake while supporting focus and energy. Use it as a complement to water, not a replacement.
Ready to Level Up Your Hydration?
Hydration is simple in theory and easy to neglect in practice. The goal is not perfection, it is consistency. A good bottle, a few smart habits and the right support on training days will take you further than any single fix.
FAQ: How Much Water Should You Drink a Day?
How much water should you drink a day?
General guidelines suggest around 2 to 2.5 litres of total fluid per day for most adults. A useful formula is 35 ml per kg of body weight. However, your actual needs depend on your activity level, body size, climate and diet. On training days or in hot weather, you will typically need more. Check our guide for a detailed breakdown of how much water you should drink a day based on your personal situation.
How many litres of water per day should I drink if I exercise regularly?
If you train regularly, add at least 500 ml to 1 litre to your baseline daily intake on workout days. For longer or more intense sessions, you may need even more. Using an isotonic sports drink or electrolytes can help you rehydrate more effectively after training.
What are electrolytes and why do they matter for hydration?
Electrolytes are minerals, mainly sodium, potassium, magnesium and calcium, that help your body balance fluids, support muscle function and enable nerve signalling. When you sweat, you lose both water and electrolytes. Replacing them matters particularly during exercise, in heat, or during longer training sessions. Browse our electrolytes range to find the right option for you.
How much water is too much?
Drinking significantly more water than your kidneys can process (roughly 0.8 to 1 litre per hour) can dilute sodium in your blood, causing hyponatraemia. How much water is too much in practice? For most people drinking consistently throughout the day, it is not a realistic concern. The risk is mainly relevant for endurance athletes drinking very large amounts over long events without electrolyte replacement.
Can you drink too much water?
Yes, technically. But can you drink too much water in day-to-day life? It is unlikely if you drink at a normal pace and spread your intake throughout the day. The greater risk for most active people is actually drinking too little. If you are training hard, focus on consistent hydration and include electrolytes where needed.
Does water intake differ between men and women?
Slightly. EFSA recommends around 2.0 litres per day for women and 2.5 litres for men from fluids alone, not counting food. In practice, activity level, body weight and climate make a bigger difference than gender. An active woman will typically need more water than a sedentary man of the same weight.
What are the signs of dehydration?
Common signs include dark urine, thirst, headaches, fatigue, difficulty concentrating, dry mouth and muscle cramps. Even mild dehydration of 1 to 2% of body weight can affect physical and mental performance. Check your urine colour throughout the day: pale yellow means you are well hydrated.
