NAPLEX (North American Pharmacist Licensure Examination) Practice Exam

How many mL are in 1 fl oz?

1. 15 mL

2. 20 mL

3. 29.57 mL

4. 50 mL

The correct answer is: 29.57 mL

A fluid ounce (fl oz) is a unit of volume commonly used in the United States and other countries. One fluid ounce is equivalent to approximately 29.57 milliliters. This conversion factor is important for pharmacists, as medication dosages are often prescribed in milliliters while some measuring devices in pharmacies may be labeled in fluid ounces. Therefore, understanding the conversion between fluid ounces and milliliters is crucial for accurate pharmaceutical calculations. Options A, B, and D are incorrect as they do not reflect the precise conversion factor between fluid ounces and milliliters. Option A (15 mL), option B (20 mL), and option D (50 mL) do not match the standard conversion rate of 29.57 mL in 1 fluid ounce.