Water Intake Calculator

The Water Intake Calculator gives you an approximate amount of water you need to consume daily to avoid dehydration. By providing inputs like full body weight and workout duration in the selected unit system, you can easily calculate the daily water intake result in no time.

Unit system
Body Weight (lbs):
Duration of Workout (min/day):

Water Intake Calculator: This Free Online Daily Water Intake Calculator will help you to estimate your adequate water intake per day. Also, you can check out the results on how many ounces of water intake per day you require to support your exercises and suitable hydration levels with the help of our water daily intake calculator. Even you can check the details like importance, factors, and how much water should you drink a day calculation with an example from the further modules.

What is the Importance of Water Intake?

For good health, you need to drink enough water every day. Dehydration can cause confusion, cause mood changes, and cause your body to overheat. Besides helping to make saliva, water intake regulates your body temperature and protects the tissues, spinal cord, and joints. 

Water intake helps expel waste through perspiration, urination, and defecation, and it helps fight off illnesses. Consuming adequate amounts will have two benefits: not only will you maintain your current state of health, but also you may improve it.

Factors Important For Calculating Water Intake

Water and other fluids can keep healthy people hydrated. For some people, drinking up to eight glasses of water a day might be enough to stay hydrated. But other people may need more. Factors that are important for water intake are as follows:- 

  • Exercise: If you do any exercise that causes you to sweat, make sure you drink extra water to replace the fluids you're losing. You have to consume water before, during, and after exercising.
  • Environment: Hot and humid weather can make you sweat and cause you to drink more fluids, and altitude can also cause dehydration.
  • Pregnancy and breast-feeding: During pregnancy and while breastfeeding, you may need to drink more fluids.
  • Illness: Drink more water if you have a fever, vomiting, or diarrhoea. Other conditions that might require increased fluid intake are urinary tract infections and bladder stones.

Water Intake Chart By Age

  Age (years) AI (milliliters/day)
Child 0–6 mths 700
7–12 mths 800
1–3 1300
4–8 1700
Female 9–13 2100
14–18 2300
19–30 2700
31–50 2700
50+ 2700
Male 9–13 2400
14–18 3300
19–30 3700
31–50 3700
50+ 3700

How to Determine Water Intake by Weight Manually?

The simple steps for calculating how much water you need to consume on a daily basis is provided here: 

  • Determine Your body weight.
  • Multiply your body weight by 2/3.
  • The determined value is water you need to drink on a daily basis.
  • Calculate your engagement in work out or exercises. (Add an additional 12 ounces of water for every 30 minutes of exercise)
  • Add both the units to calculate the total amount of water you should consume.
  • Finally, the determined value is the total Water Intake requirement for your body.

Solved Example on Calculation of Water Intake


The total bodyweight of Joe is 180 pounds and he spends 100 minutes every day in exercise. Calculate the water intake requirements for Joe.


Given, The weight of Joe = 180

The calculation will be as follows:

180× 2/3 = 120 ounces (3.55 liters) of water per day.

Since he spends minutes every day in exercise. 

Thus, additional water intake requirement per day = 100 / 30 × 12 = 40 ounces of additional water per day.

Thus, the total water intake requirement will be:

120 ounces + 40 ounces = 160 ounces (4.73 liters) of water per day.

To save yourself the time and headache of doing a ton of math, we have built calculators to do that for you. Visit arithmeticcalculator.com and try out other combinations to find the right answers for your problems.

FAQs On How Much Water Should I Drink Calculation?

1. How much water should you drink based on your weight?

We must drink between 3 to 4 liters of water per day. For example, if a person weighs 68 kgs then he should drink 2 to 4 liters of water.

2. How much ml should you drink a day?

The prescribed daily intake of,3000 ml for men and of 2,200 ml for women is sufficient. Higher fluid intake prevents kidney stones but otherwise, it does not have any convincing effects. 

3. How much water should a 90kg man drink?

To calculate this multiply 0.033 to weight i.e 90kgs it results in approximately 3 liters of water but if you are an active person then 1.5 liters is also sufficient. 

4. How do I calculate my water intake?

To calculate your water intake based on your weight, you can follow the steps given below:

  1. Find out your weight (in pounds) and divide it by 2.2.
  2. Multiply the 2.2 subjects to your age. (If your age <30, multiply by 40, age>55, multiply by 55, age is between 30-55, multiply by 35) 
  3. Now, divide the sum by 28.3.
  4. Finally, the determined value is the required ounces of water you should drink each day.