Water Intake Calculator: How Much Water Should I Drink?

Medically reviewed by Gabrielle Kane, RDN, CSP, LD Gabrielle Kane Gabrielle KaneRDN, CSP, LD facebook_iconinsta_icon
Written by , Senior Health & Wellness Writer Payal Karnik Senior Health & Wellness Writer Experience: 2.5 years
Edited by , Senior Editor Arshiya Syeda Senior Editor Experience: 7 years
Fact-checked by , Senior Health & Wellness Writer Sindhu Koganti Senior Health & Wellness Writer Experience: 6 years

The water intake calculator is a simple tool to estimate the amount of water you should drink per day. Drinking enough water is essential for maintaining homeostasis and normal body functions (1). According to the Institute of Medicine, women should drink 2.7 liters of water per day and men 3.7 liters of water per day (1). Find out how much water should you drink per day below:



Note: This calculation is for guidance purposes. Talk to your doctor if you have a medical condition or are training for a competition, pregnant, or lactating.

How To Calculate Daily Water Intake

You can also calculate your daily water intake using these simple steps:

1. Multiply your weight by ⅔.

For example, if you weight 150 pounds:

2/3 * 150 = 100 ounces or 2.95 liters of water

2. Determine how much you sweat when you workout.

The more you sweat, the more water you need to consume. Add 12 ounces of water per 30 minutes of exercising. If you work out for 45 minutes every day, here’s how to calculate the extra water intake:

45/30 = 1.5

1.5 * 12 = 18 ounces (0.5 L) of extra water per day

3. Total Water Intake

Add the two values to get the total amount of water to drink per day:

2.95 liters + 0.5 liters = 3.45 liters of total water per day


100 ounces + 18 ounces = 118 ounces of water per day


12.5 cups + 2 cups = 14.5 cups of water per day

Note: This formula is for guidance purposes. Drink water according to your thirst levels. Your total water intake also depends on your health and whether you are pregnant or breastfeeding.

What Factors Affect Water Intake?

The factors that affect daily water intake are:

  • Activity level
  • Age
  • Weight
  • Climate or environment
  • Pregnancy or breastfeeding
  • Health and disease status
  • Stress

What Are The Signs Of Not Drinking Enough Water?

  • Dry skin and lips
  • Constipation
  • Bad breath
  • Headache
  • Low immunity
  • Bad skin health
  • Decreased urination
  • Fatigue

What Are The Benefits of Drinking Enough Water Daily?

The Centers for Disease Control and Prevention (CDC) reports that drinking enough water is beneficial in the following ways (2):

  • Helps maintain ideal body temperature.
  • Gets rid of toxins and wastes through sweat, urine, and bowel movement.
  • Protects sensitive tissues and the spinal cord.
  • Lubricates the joints.
  • Water also helps prevent nutrition-related non-communicable diseases (3).

How Much Water Should You Drink Based On Your Weight?

To determine the amount of water you should drink based on your weight, follow these simple steps

  1. Divide your weight (in pounds) by 2.2.
  2. Multiply the result with 40 (if your age is below 30) or 35 (if your age is 30-55) or 30 (if you are over 55 years).
  3. Divide the result by 28.3.
  4. The result you get is the ounces of water you must drink per day. Divide the amount by 8 to determine the number of cups of water to drink per day.

How Much Water Should You Drink Based On Activity Level?

The more you sweat, the more water you must drink. As a rule of thumb, add 0.3-0.5 liters (12-15 ounces or 1.5 to 2 cups) of water for every 30 minutes of workout.

Remember, your thirst may also differ depending on the type of exercise you do. For example, you may slow walk or do HIIT for 30 minutes. Of course, you will sweat more while doing HIIT. In that case, you’d need to drink more water.

How to Make Drinking Enough Water A Habit?

  • Drink water when you wake up – Drink a glass of water as soon as you wake up in the morning. Do it for 3 weeks consciously, and it will become a habit.
  • Drink detox water – Add slices of cucumber, strawberry, ginger, mint, or any other fruit/herbs in your water. It looks attractive and tastes delicious!
  • Carry a water bottle with a sipper – Water bottles with sippers are convenient and stylish. Sip water every 30 minutes, whether you are on the go or working at your desk.
  • Set reminders – If you keep forgetting to drink water, set reminders to do so every 30-45 minutes.
  • Consume fruits and veggies – Fruits and veggies naturally contain water, which will help rehydrate your body.
  • Consume soup – Clear soups are best for consuming water through food. Prepare delicious chicken or vegetable clear soup to get the nutritional benefits and stay hydrated.

Side Effects Of Overhydration

  • Electrolyte imbalance (hyponatremia or low sodium concentration in the blood)
  • Nausea
  • Vomiting
  • Headache
  • Stomachache
  • Disorientation
  • Seizures
  • Coma

Frequently Asked Questions

Why do I pee so much when I drink water?

If one drinks excess water, the body tries to get rid of the extra water. Hence, there is higher urine output.

Is it OK to drink 1 liter of water at once?

Yes, 0.8 to 1 liter of water can be taken at once. But any amount exceeding this limit may cause water intoxication.

Should we drink water on an empty stomach?

Yes, water can be had on an empty stomach. It helps in cleansing bowels and helps manage constipation.

Can sleeping too much cause heart problems?

Yes, sleeping for more than 8 hours may increase the risk of heart problems in adults.

Does tea count as water intake?

No, tea cannot be counted as water intake. However, it can be considered in one’s total fluid intake.

When should you not drink water?

Water is a safe drink that can be had anytime during the day. However, having it more during the night may disrupt sleep. Hence, avoid taking water at least 2 hours before sleep.


Articles on StyleCraze are backed by verified information from peer-reviewed and academic research papers, reputed organizations, research institutions, and medical associations to ensure accuracy and relevance. Read our editorial policy to learn more.

  1. Narrative Review of Hydration and Selected Health Outcomes in the General Population https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356561/
  2. Water & Nutrition, Centers for Disease Control and Prevention. https://www.cdc.gov/healthywater/drinking/nutrition/index.html
  3. Water, Hydration and Health, Nutrition reviews, US National Library of Medicine, National Institutes of Health. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908954/

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