Drinking enough water every day is important for health and wellbeing. The common recommendation is to drink 8 glasses of water per day, but how much is that in milliliters (mL)? Here is a quick overview of how to calculate the volume of 8 glasses of water in mL.
Quick Answer
8 glasses of water is equal to about 2000 mL. This is based on 8 glasses at 8 ounces (237 mL) per glass.
Calculating 8 Glasses of Water in mL
To figure out how much 8 glasses of water is in mL, we need to know two things:
- How many glasses of water are recommended per day (typically 8 glasses)
- How much water is in 1 glass in mL
Let’s look at each of these:
How Many Glasses of Water Per Day?
The recommendation from health organizations is typically to drink around 8 glasses of water per day. This is based on the Institute of Medicine (IOM) adequate intake levels, which recommend:
- Men: 3.7 liters (about 15.5 cups) of total water per day from all foods and beverages
- Women: 2.7 liters (about 11.5 cups) of total water per day from all foods and beverages
Since these recommendations are for total water intake from all sources, drinking 8 glasses of water helps contribute to meeting the adequate intake levels.
How Much Water is in 1 Glass?
A standard glass size used for water and other beverages is typically 8 ounces. Here is how much 8 ounces of water equals in mL:
- 1 ounce = 29.57 mL
- 8 ounces = 8 * 29.57 mL = 236.56 mL (rounds to 237 mL)
So 1 glass at 8 ounces contains approximately 237 mL of water.
Calculating 8 Glasses in mL
Now we can calculate how much 8 glasses is in mL:
- 8 glasses
- 237 mL per glass
- 8 * 237 mL = 1896 mL
Rounding the 1896 mL to a simpler number gives us 2000 mL.
So 8 glasses of 8 ounces each is equal to about 2000 mL of water.
8 Glasses of Water in Liters and Quarts
We can also convert 2000 mL to other volume units:
- 2000 mL = 2 liters
- 2000 mL = 2.11 quarts
Variation in Glass Size
The exact amount of water in 8 glasses can vary slightly based on the size of glass used. Some other common glass sizes include:
| Glass Size | Volume per Glass in mL |
|---|---|
| 12 ounces | 355 mL |
| 16 ounces | 473 mL |
| 10 ounces | 296 mL |
So if using 16 ounce glasses, 8 glasses would equal about 3784 mL instead of 2000 mL.
Drinking 8 Glasses Per Day
Drinking about 8 glasses or 2 liters of water daily is a good target for most healthy people living in temperate climates. Here are some tips for getting in your 8 glasses:
- Carry a reusable water bottle with you throughout the day for easy sipping access
- Choose water over sugary drinks like soda, juice, and sports drinks
- Set reminders on your phone or smart watch to drink water at regular intervals
- Infuse your water with fruits or herbs for flavor if you don’t like plain water
- Opt for water when dining out instead of ordering other beverages
Keep in mind that you may need more or less water than 8 glasses depending on factors like your activity level, climate, health conditions, and if you are pregnant or breastfeeding. Listen to your body’s thirst signals and opt for water when you feel thirsty.
Water Intake Recommendations
General recommendations for daily total water intake from foods and beverages for various groups are:
| Group | Total Water Recommended (Liters) |
|---|---|
| Men | 3.7 |
| Women | 2.7 |
| Pregnant Women | 3.0 |
| Breastfeeding Women | 3.8 |
| Children 4-8 years | 1.7 |
| Children 9-13 years | 2.4 |
Drinking about 8 glasses of water from beverages can help contribute to meeting these total daily water intake recommendations.
Signs of Dehydration
Some signs that you may be dehydrated and need to drink more water include:
- Thirst
- Dry mouth
- Fatigue
- Dizziness
- Headaches
- Reduced urination and dark yellow urine
Pay attention to these signs from your body and be sure to drink extra water if you notice them.
Too Much Water Intake
Drinking more than about 2.5 liters (12 cups) in a short timespan may cause hyponatremia or low sodium levels. Some signs of hyponatremia include:
- Nausea and vomiting
- Headache
- Fatigue
- Restlessness
- Muscle cramps
- Confusion
Unless you are an athlete training extensively in hot conditions, drinking well over 8 glasses is not necessary and may cause problems.
Water vs Other Beverages
Plain water is the healthiest beverage option to contribute to daily water intake needs. Other beverages like milk, juice, coffee and tea can also add to hydration, but contain added sugars, calories, and caffeine that water does not.
Sugary drinks like soda, fruit juice, sports drinks, and energy drinks are high in added sugar and calories with little hydration benefit. These are best limited in a healthy diet.
Tracking Your Water Intake
To make sure you are drinking enough over the day, you can track your water intake in a few ways:
- Use a water tracking app to log each glass or bottle
- Note number of glasses on a piece of paper or whiteboard
- Set hourly reminders to drink a certain amount
- Carry a water bottle and refill a certain number of times per day
Find a tracking method that works best for your lifestyle. Some simple options require minimal effort.
Water Intake for Exercise
When exercising, especially in hot weather, extra water is needed to replace sweat losses. Some tips include:
- Drink 2-3 cups of water in the hours before exercising
- Sip 1⁄2 to 1 cup every 15-20 minutes during exercise
- Weigh yourself before and after exercise to guide hydration needs
- Drink 2-3 cups after exercise to rehydrate
Thirst is a good indicator of when you need more water during exercise. Urine color can also guide hydration, with light yellow being well hydrated.
Water Intake on Keto and Low Carb Diets
Following a ketogenic or very low carb diet often leads to increased water needs and faster dehydration. Tips for staying hydrated include:
- Drink an extra 1-2 glasses daily
- Consume bouillon cubes dissolved in warm water
- Include water-rich foods like cucumber, berries, zucchini
- Monitor urine color and drink more if dark yellow
Electrolyte supplements containing sodium, potassium and magnesium can also help maintain hydration on low carb diets.
Water Intake at High Altitudes
At higher elevations, the body loses more water. Recommendations for high altitude hydration include:
- Drink an extra 1-2 glasses of water daily
- Avoid alcohol and caffeinated drinks which have diuretic effects
- Monitor headache, nausea and fatigue as signs of dehydration
- Acclimatize for a few days before intense physical activity
Consuming extra water can help counteract the dehydrating effects of high altitude environments.
Common Questions
Should you drink water even when not thirsty?
Drinking water only when thirsty is generally fine for healthy adults. But some groups like the elderly may need reminders to drink even when not thirsty as the thirst sensation diminishes with age.
Does water intake include foods?
The recommended daily water intakes refer to total water from both foods and beverages. Fruits and vegetables especially can contribute to hydration.
Do you need extra water in summer?
Yes, in hot summer weather, extra water of 1-2 glasses is recommended to replace sweat losses from heat and increased activity.
Is coffee and tea hydrating?
Yes, caffeinated beverages like coffee and tea can contribute to hydration. But moderation is key as too much caffeine can have dehydrating effects.
Conclusion
To summarize, drinking 8 glasses of water daily provides roughly 2 liters of fluid, which helps meet general water intake recommendations for good health and hydration. Needs can vary based on climate, activity level, and health conditions so it is also important to listen to your body’s thirst signals. Getting sufficient water intake from beverages and foods is vital for sustaining normal bodily functions and wellbeing.
