Water Intake Calculator How much water should I drink per day?

Water Intake Calculator How much water should I drink per day?

How much water/fluids should I drink? This question has many answers nowadays. At least on the internet you can find more than enough of them. What amount of water reflects the reality and the real need of our body? What is healthy water intake?
Enter your body stats
The calculations are indicative

Drinking regime - Calculator: how much water should I drink per day?

What is a drinking regime and what is its importance?

Drinking is the supply = replenishment of water to a person's body. In doing so, it must cover the daily water needs and losses by the body.

Water is necessary for the human body, and the human body cannot produce it on its own. And we already know from school that about 60-70% of the body is made up of water.

Drinking little fluids = I will be tired, weak, literally drained. Dehydrated/dehydrated.

Of course, neither is the opposite - too much water is not good for the body.

We need to take into account individual needs and overall physical or mental stress. Not least the environmental conditions. 

And also - how old we are (in relation to childhood and adulthood).

Once it's less and once again more water.

All it takes is for the temperature outside to rise above 30 and we are immediately talking about a different amount of water being exhaled and sweated out.

And speaking of the amount of fluids that normally leave our bodies in a day, so:

  • 800 - 1400 ml of water goes out during urination
  • 600 - 800 ml of water in the form of steam
  • 500 ml of water leaves by sweating
  • and about 100 ml of water is passed in the stool
  • total = 2000 to 2800 ml

Values rise sharply with high physical exertion and during hot summer days. Then the water loss should be estimated at 3 to 5 times.

The increase in loss should therefore be offset by increased revenue.

We are familiar with the statement that we should drink about 1.5 - 2 litres of water a day.

How do I check the correct amount of water to drink in one day?

Easy. Use our calculator.

And how is the daily water requirement calculated? 

This is based on the age-per-kilogram of body weight.

  • you should take into account that the recalculation takes into account ideal conditions: 
    • ambient temperature 22 °C
    • relative humidity around 60 % 
    • effortlessly and with unnoticeable sweating

Drinking patterns by weight and age in the table, even for children

A brief summary gives the values under ideal conditions.

Table: How much water should I drink? Amount by age per 1 kg of body weight

Age period  Approximate amount of fluid per day per 1 kg of body weight
Infant 120 - 180 ml 
Child from 1 to 3 years old 100 - 125 ml of water
Child from 4 to 7 years old 90 - 110 ml of water
Child from 8 to 12 years old 70 - 100 ml of water
Children and adolescents aged 13 to 18 40 - 60 ml of water
Adults 20 - 45 ml of water

And thus, I am an adult. I have 70 kilograms of body weight. I should drink between 1400 (1.4 litres) and 3150 ml (3.15 litres) of fluid. Let's think more along the lines of 2 - 2.5 litres.

I have a child who is 5 years old and weighs about 20 kg. He should drink about 1800 ml (1.8 litres) to 2200 ml (2.2 litres) in 24 hours. 


  • It is necessary to drink more often in smaller quantities, for example a glass of water every hour or so, or 10 x 2.5 dcl of water, everyone can set their own frequencies and quantities.
  • In the morning after waking up, it is advisable to drink about 3 dcl of water.
  • The main meal should not be washed down with too much water.
  • Pouring water from a bottle can improve clarity.
  • The term 'suitable liquid' means drinking water or table spring water - non-carbonated.
    • Inappropriate beverages include, for example, sweetened lemonades, cola drinks, flavoured mineral and carbonated drinks, nectars, juices - their intake should be limited, more as a treat than as a form of drinking.
      • Their excessive intake is risky for the development of obesity and other health complications associated with it, in addition, sweetened beverages promote the development of dental caries.

Note: Do not forget to increase the amount of liquids in the environment where heating and air conditioning are used. Both situations dry out the air and thus also the mucous membranes of the nose and mouth = increased need for fluids.

Is my water intake too low? 

How do I know I haven't had enough to drink? Symptoms such as:

  • feeling thirsty
  • fatigue, malaise, weakness
  • dark urine and urinating small amounts of urine
  • dry skin and lips, tongue
  • body tremours
  • pain and dizziness
  • low pressure and rapid pulse, up to collapse
  • coffee and tea, and also alcohol - increase the amount of urine produced (individually)

Decreased mental performance, fatigue, drowsiness or headache are often the first signs of insufficient water intake. 

In addition, you will have a reduced frequency of urination. You will urinate less urine, which will be dark yellow and may smell more.

On the contrary, sufficient water will ensure good physical and mental vitality. It will improve your mood, emotions, performance, overall well-being.

How much water is a lot? Water poisoning - can fluids be overdone?

It is also possible to deliver too much fluid into the body. 

How much is a lot?

If you are at rest and have no activity, you don't drink 5 litres of water. Unless you have a good reason for it. 

Reduction diet? And is it even right?

10 litres can already put a significant strain on the heart and kidneys.  

So you can catch up to water poisoning in a very short period of time, but also if you exceed reasonable limits in the long term.

Our body tries to balance all substances and minerals in a reasonable way. When you drink excessive litres of water over a long period of time, you will overestimate your mineral levels. Which can have fatal consequences.

What causes excessive water intake?

Sodium deficiency, i.e. hyponatraemia, is dangerous when the blood sodium level is below 130 mmol/l.

Water intoxication can manifest as... 

Headache, fatigue, nausea vomiting, muscle cramps, or disorientation. 

Do not endanger your health and life.

In conclusion

Interestingly, in several publications one can find information that is somewhat contradictory. 

An example is that some experts do not include food and, for example, milk, soup, tea or coffee in the total daily intake.

However, on the other hand, there are those who include these items as well. They state that food covers about 20% of the value of our fluid intake (fruits, vegetables, milk). 

Similarly with the 2 litre claim. 

Some sources state that an intake of 2 litres per day lacks sufficient scientific evidence. 

Who is supposed to know? And what should I remember so that I don't have to "carry a calculator" with me?

6 - 8 cups should be my sufficient limit in one day. 

  • if the glass is 2,5 dcl = 1,5 to 2 litres
  • if the glass is 3 dcl = 1.8 to 2.4 litres
  • for men, about 2 litres, and for women, about 1.6 litres of water per day
  • the amount increases depending on daily activities

Other publications advise that men should drink about 15.5 cups (equivalent to about 3.6 litres) and women 11.5 cups (about 2.6 litres) of fluid per day = about 2.3 dcl of water per cup.

Sufficient drinking / I drink enough = I rarely feel thirsty and my urine will be light yellow to colourless/clear.

Insufficient drinking / I don't drink enough = I urinate little and dark yellow urine, I feel thirsty and my general vitality decreases.

Pay attention to the peculiarities of each of us.

If a person is being treated for heart failure and has non-functioning kidneys, these calculations are invalid. The amount of fluids per day must be consulted with a doctor.

Read more about drinking (including employer responsibilities) and dehydration in the following articles:

Important notice:

Please remember that the results of our health calculators and analyzers are for guidance purposes only. They are not a substitute for a professional examination or the advice of a doctor, pharmacist or other health care professional.

Each person is unique, and everyone's needs may vary. Calculators and analyzers have limitations and do not provide a comprehensive individual view of health.

Their use is at your own risk. Neither the site operator nor the author is responsible for misuse and misinterpretation of information obtained through their use. By using the calculators and analyzers, you agree to these terms and conditions and neither the operator nor the author shall be liable for any consequences.

You are advised to consult a professional for your medical condition. Remember that health is an important topic and any decisions should be made in consultation with a professional.

This calculator/analyzer is not a medical tool or medical aid. Consult your doctor about your health problem.

Embed this calculator on your site for free

Simply copy the HTML code to your page. The code is copied in the same way as the embed code of the youtube video. If you have wordpress, you can put it in the HTML field.
The requirement for embedding the calculator is to place the source and dofollow link as specified in the code.

<script src="https://medicspark.com/frontend-assets/scripts/iframe-message.js" async></script><iframe id="medicspark-water-intake-calculator" class="medicspark-calculator-iframe" src="https://medicspark.com/calculators/water-intake-calculator/embed/" style="border: 0;overflow: hidden;width: 100%" scrolling="no"></iframe><a class="medicspark-calculator-copyright" href="https://medicspark.com/calculators/water-intake-calculator">Water Intake Calculator How much water should I drink per day? from MedicSpark.com - view explanations and details</a>
fshare on Facebook