12 oz equal how many ML?

Answer 1

There can be no equivalence. An ounce is a measure of mass. A millilitre is a measure of volume. The two measure different things and, according to basic principles of dimensional analysis, conversion from one to the other is not valid. If the question had been about fluid ounces instead of ounces, or if the question had been about milligrams instead of millilitres, it would have been possible to convert but the question was not either one of those - or other valid versions.

Answer 2

12 fluid ounces is 354.88 milliliters.