How much water a person needs depends on body weight, activity level and the weather. Here is a simple way to estimate it, and the signs that your body is running short.
Water makes up most of your body weight and is involved in almost everything it does: regulating temperature, carrying nutrients, flushing out waste. So how much should you drink each day?
There is no single number for everyone
How much water you need depends on your body weight, how active you are, the weather and your state of health. Someone working outdoors, training hard or getting through a hot day needs more than someone sitting in an air-conditioned office.
A simple way to estimate it
A widely used rule of thumb is roughly 30–40 ml of water per kilogram of body weight per day, counting the water in your food and other drinks. If you have a heart or kidney condition, ask your doctor what is right for you.
Signs you are short of water
- Thirst, a dry mouth, chapped lips.
- Dark urine, passing less of it.
- Tiredness, headaches, trouble concentrating.
Tips for drinking enough
- Have a glass of water when you wake up.
- Keep a bottle on your desk and sip through the day.
- Do not wait until you feel thirsty.
This article is for general information and does not replace medical advice.
