For the average 70 kg man, 60% of the total body weight is comprised of water, equaling 42L.
Total body water = 70 kg × 0.60 = 42 L (280 mOsm/kg [280 mmol/kg]).
Weight. 60% of our body is water. For a person weighing 70kg, that means 42 kg or 42 litres!
A more calculated way to look at it is – drink a litre of water per 25kg of bodyweight, so if you weigh 50kg that's around 2 litres of water per day and if you weigh closer to 75kg you should be drinking broadly 3 litres per day.
The volume of extracellular fluid in a young adult male of 70 kg (154 lbs) is 20% of body weight – about fourteen liters. Eleven liters are interstitial fluid and the remaining three liters are plasma.
The average PV in a normal 70 kg adult is approximately 3.5 L (50–55 mL/kg). If the PV and hematocrit are known, the blood volume can be calculated as PV/(1 – hematocrit) and is approximately 70–80 mL/kg in healthy adults.
1 Kg of water approximately equals 1 L.
The U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is: About 15.5 cups (3.7 liters) of fluids a day for men. About 11.5 cups (2.7 liters) of fluids a day for women.
2 liters is 67.6 ounces, or about half a gallon (US).
Looking at it in the simplest way possible, a glass of water is already one cup, and a cup equals 8 ounces cups of water. So taking it eight times a day would be64 ounces of water, which is almost 2 liters.
An adult needs an average of 1.5 to 2 liters of fluid per day in the form of drinks. Exactly how much fluid you need depends on your age, temperature, exercise, what you eat and your state of health.
One litre of water has a mass of almost exactly one kilogram when measured at its maximal density, which occurs at about 4 °C. Similarly: one millilitre (1 mL) of water has a mass of about 1 g; 1,000 litres of water has a mass of about 1,000 kg (1 tonne).
Daily fluid intake
The Eatwell Guide recommends that people should aim to drink 6 to 8 cups or glasses of fluid a day. Water, lower-fat milk and sugar-free drinks, including tea and coffee, all count.
Here is one more reason to enjoy that morning cup of joe: “Coffee counts toward your daily water intake,” says Lauren DeWolf, MS, RD, a registered dietitian with Sharp Rees-Stealy Medical Centers. The water in coffee, tea and other caffeinated beverages helps us meet our daily fluid needs.
As a general rule, you can use this simple calculation. Water (in litres) to drink a day = Your Weight (in Kg) multiplied by 0.033. For example, if you are 60kg, you should drink about 2 litres of water every single day. At 90kg, you'll around about 3 litres of water.
Women should have about 2 litres (8 cups) of fluids a day, and men about 2.6 litres (10 cups). Women who are pregnant or breastfeeding need more fluid each day than other women. Dehydration can happen when the body's fluids are low. It can be life threatening, especially to babies, children and the elderly.
Your weight is one variable that changes the amount of water you should be drinking. To help you establish a baseline, you can use the following rule-of-thumb equation described in U.S. News & World Report. In short, the equation tells you to take half your body weight, and drink that amount in ounces of water.
The body needs water to function correctly, but drinking too much too fast can have serious health consequences. The kidneys can only remove 0.8 to 1.0 liters of water per hour, and a very high water intake can upset the body's electrolyte balance.
Drink water before each meal: Instead of washing down your meal with water, which really doesn't help with your digestion btw, try drinking a glass or two 15 minutes before meal time. Not only will you feel fuller and eat less, but it'll also help with digestion. Make it visible: If you don't see it, you won't need it.
Under the usual conditions of life, 3 – 4 liters of fluids a day will provide 2.5 to 3 liters of urine volume, and this is enough. The average healthy adult bladder holds about 1/2 liter, so this means 7 – 9 bathroom trips in 24 hours.
One litre of water has a mass of almost exactly one kilogram when measured at its maximal density, which occurs at about 4 °C. It follows, therefore, that 1000th of a litre, known as one millilitre (1 mL), of water has a mass of about 1 g; 1000 litres of water has a mass of about 1000 kg (1 tonne or megagram).
Therefore, the mass of the liquid occupying 20 liters is 18kg.
One kilogram (1 kg) is equivalent to 1000 grams and one litre (1 L) is equivalent to 1000 millilitres, so 1 kg is equivalent to 1000 millilitres or 1 litre. Therefore, 1 kg is equal to 1 litre.