How Many Ounces of Water Per Day?
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.