There are a number of online calculators to do this automatically, and for a precise answer, that is best, but for a rough measure 30 ml equals one ounce. Precisely, one ml equals 0.033814 u.S. ounces.
1 mL is equal to 0.0338 fluid ounces. So, for example, if you want to convert 200 mL to fluid ounces, you need to multiply 200 by 0.0338, which would be about 6.76 fluid ounces.
