How many milliliters are in 1 fluid ounce?

• A. 15 mL
• B. 20 mL
• C. 30 mL
• D. 60 mL

Answer: (C)

One fluid ounce is about 29.57 milliliters, and in medical practice this is usually rounded to 30 mL for easy dosing calculations. So 30 mL is the closest and most practical equivalent to one fluid ounce. The other options are notably off: 15 mL is about half, 20 mL is not close to the true value, and 60 mL would be double.