How much water should you really drink each day? We’ve heard for a long time that it’s eight cups. Recent studies have revised the amount so often than most of us are left confused. The latest research from the medical research center at the Mayo Clinic in Minnesota set the bar at 13 cups a day on average for men and nine cups of water for women. Nobody disputes the importance of consuming water. The beverage has benefits from clearing up the complexion to help us feel energized. If you don’t get enough, you may suffer symptoms of dehydration that include dry skin, a headache, dizziness and even fainting.

There’s one easy way to judge whether you’re getting sufficient water during the day. When you imbibe enough, your urine should be a very pale color rather than a deep yellow. Exercise and diet can make a difference.

Eating foods high in water, such as watermelon, cucumber and celery, can help flush toxins from your body. Eating salty foods has the opposite effect. Your body will retain fluids to help dilute the sodium, and that’s why eating salty foods makes you thirsty.

You’ll need to drink more water to replace the liquid you’ll lose when you exercise. The American College of Sports Medicine recommends drinking an extra 12 ounces of water for every 30 minutes of exercise.

Despite knowing that we require water, most of us don’t know how much we really need. The truth is that there’s no one-size-fits all formula. Some authorities now recognize that every person’s body is different. They’re recommending a simple scientific formula to help us figure how much water each individual needs to drink every day.

Here’s the formula for how much water you should be drinking:

Step 1: Take your weight (in pounds) and divide it by 2.2.

Step 2: Multiply that number by your age.

Step 3: Divide that sum by 28.3.

Step 4: Your total is how many ounces of water you should drink each day.

Divide that number by eight to see your result in cups.

Read More: How much water you should REALLY drink in a day?