There is an approximate calculation of 16 ounces when converting 500 milliliters. Each milliliter is 0.033814 ounces, and to perform this conversion, one would have to multiply 0.033814 by 500 to get the exact answer. The exact calculation is 16.907 fluid ounces.
The measurement of milliliters is more common in the United Kingdom and Europe, and the measurement of ounces is more common in the United States. It is commonly recommended in the United States to drink eight 8-ounce glasses of water daily, so therefore the recommendation in the United Kingdom would be to drink eight 237-milliliter servings of water per day.