First, calculate how many mg you take in a day. 24/8=3, and 3*400=1200, so assuming you don't miss any, you would take 1200 milligrams in a day. You can change this to 1.2 grams. The conversion rate from grams to ounces is about .035, so you would get 1.2*.035. That makes .07*.6, which is 42 with 3 decimal points to the left. That's about .042 ounces.