For this case we must perform a conversion of milliliters to ounces.
By definition we have to:
1 US liquid ounce equals 29.5735 milliliters. Then, making a rule of three:
1 oz. ---------> 29.5735 milliliters
x -------------------> 650 milliliters
Where "x" represents the number of oz equivalent to 650 mL.

Thus, 650 mL equals 21.9791 oz.
Answer:
650 mL equals 21.9791 oz.