How Many Ounces of Water Per Day?
Health guidelines recommend approximately 64–80 fluid ounces of water per day. The classic '8 glasses a day' equals 64 fl oz (1.9 liters). The National Academies recommends about 91 fl oz (2.7 L) total daily water for women and 125 fl oz (3.7 L) for men — including water from food. Plain drinking water intake is typically 64–80 fl oz (8–10 cups).
Quick Answer
Health guidelines recommend approximately 64–80 fluid ounces of water per day.
64 fl oz = 8 cups = 1.9 L (minimum guideline)
Understanding the Conversion
The classic '8 glasses a day' equals 64 fl oz (1.9 liters). The National Academies recommends about 91 fl oz (2.7 L) total daily water for women and 125 fl oz (3.7 L) for men — including water from food. Plain drinking water intake is typically 64–80 fl oz (8–10 cups).
Formula
64 fl oz = 8 cups = 1.9 L (minimum guideline)
Common Examples
| Description | Value |
|---|---|
| 8 × 8 oz glasses | 64 fl oz per day |
| Standard water bottle (16.9 oz) | Drink 4–5 per day |
| 32 oz Nalgene bottle | Drink 2 per day for 64 oz |
Quick Reference Table
Use this table for quick conversions between day (water intake) and fluid ounces:
| day (water intake) | fluid ounces |
|---|---|
| 1 | 64 |
| 2 | 128 |
| 5 | 320 |
| 10 | 640 |
| 25 | 1,600 |
| 50 | 3,200 |
| 100 | 6,400 |
Frequently Asked Questions
How Many Ounces of Water Per Day?
Health guidelines recommend approximately 64–80 fluid ounces of water per day. The classic '8 glasses a day' equals 64 fl oz (1.9 liters). The National Academies recommends about 91 fl oz (2.7 L) total daily water for women and 125 fl oz (3.7 L) for men — including water from food. Plain drinking water intake is typically 64–80 fl oz (8–10 cups).
What is the formula to convert day (water intake) to fluid ounces?
The formula is: 64 fl oz = 8 cups = 1.9 L (minimum guideline). To convert, multiply the number of day (water intake)s by 64 to get the equivalent in fluid ounces.
How do I convert fluid ounces to day (water intake)?
To convert fluid ounces to day (water intake), divide the number of fluid ounces by 64. For example, 320 fluid ounces equals 5 day (water intake)s.