The conversion factor for weight units grams to ounces (oz) is 0.0352739619. For troy ounces, it is 0.0321507466. To find out how many ounces in a gram, multiply by the conversion factor or simply use the converter below. 1 Gram = 0.0352739619 Ounce. Gram is a commonly used metric system unit of mass. It is one thousandth (1/1000) of the metric system base unit, kilogram.