How much water do you really need to drink each day?

The sweltering summer days mean we spend more time outdoors, from walking and playing sports to picnicking. However, under the intense heat, staying hydrated becomes more important than ever.

Rising temperatures cause the body to sweat more, increasing the risk of dehydration if you don't replenish fluids promptly. But the question is, exactly how much water should we drink each day? Is the popular advice of "8 glasses of water a day" (about 1.9 liters) really reliable, or just another outdated health myth?

Nutrition expert Renee Fitton, Director of Education at L-Nutra, a US-based nutritional technology company, suggests that drinking eight glasses of water a day may be a good starting point, but it's not always suitable for everyone.

How much water do you really need to drink each day?

According to nutritionist Renee Fitton, there's no one-size-fits-all formula when it comes to daily water needs. The amount of water required depends on many factors such as body size, level of physical activity, gender, medications being taken, climate, health status, and even the altitude at which you live.

For years, the "eight glasses of water a day" rule, equivalent to about 1.9 liters, has been passed down as a health adage. However, Fitton says there is no specific scientific basis to support this advice.

In reality, it's just one of those widely repeated "health myths" that most of us take for granted. While not harmful, 1.9 liters a day might be too much for some and too little for others.

“For some people, such simple guidelines can help them maintain good habits. If drinking eight glasses of water a day helps someone stay hydrated, that’s a positive starting point. But I wouldn’t consider it the gold standard,” Fitton shared.

Currently, there is no official and unified recommendation on the optimal amount of water each person should drink daily, as each individual has different needs.

However, the National Academy of Sciences, Engineering, and Medicine (NAM) recommends an "adequate water intake" of approximately 3.7 liters for men and 2.7 liters for women.

Notably, this figure includes not only filtered water, but also liquids from other beverages such as tea, milk, sports drinks, and even coffee, along with water from foods like fruits, vegetables, soups, or oatmeal.

In other words, the amount of water you consume each day comes from many sources, and how you distribute it depends on your personal habits and needs.

While there are no absolute numbers that apply to everyone, one thing is certain: listening to your body, maintaining a reasonable level of thirst, and combining this with a balanced diet will help you effectively manage dehydration, especially during the hot summer months.

When should you drink more water than usual?

Not everyone needs the same amount of water each day, and in some cases, your water needs may increase significantly. Here are some common reasons why you might need to drink more water than usual.

1. You have a job that involves a lot of physical activity.

If you frequently travel or work outdoors, especially in hot weather, your body will sweat more and become dehydrated more quickly.

The U.S. Centers for Disease Control and Prevention (CDC) recommends drinking about one cup of water every 15–20 minutes when working in high temperatures. Drinking water before and after work is also important to maintain stable hydration levels.

2. You exercise regularly.

Even if you don't do manual labor but still exercise regularly, whether in the gym or through outdoor activities like running, cycling, or yoga, you still need to drink more water than usual. The body loses water during exercise, even in cold weather, so timely rehydration is essential.

3. You live in a place with a hot, dry climate.

High temperatures and dry air increase the rate of water loss through the skin and breath. People living in desert or low-humidity climates often need to drink more water than those in tropical or temperate climates.

4. You are pregnant or breastfeeding.

Pregnant women need more water to support blood circulation, nutrient absorption, and to nourish the fetus. For breastfeeding women, adequate hydration also helps the body produce breast milk more consistently and effectively.

5. Your urine is dark in color.

According to nutritionist Renee Fitton, observing the color of your urine is one of the simplest and most accurate ways to assess hydration levels throughout the day. Ideally, urine should be light yellow. If the color changes to dark yellow or amber, it's a clear sign of dehydration.

6. You have signs of dehydration.

The body always signals dehydration with symptoms like dry mouth, chapped lips, muscle cramps, headaches, or unexplained fatigue. “Water plays a vital role in all life processes. When dehydrated, the body cannot function optimally, and this can manifest in different ways in different people,” Fitton emphasized.

While fixed numbers aren't always necessary, correctly identifying situations where increased water intake is needed will help you be more proactive in taking care of your health, especially during the hot summer months.