Choose silver prices by the gram or from seven other weights of measurement from milligram, kilogram, grain, ounce, troy ounce, carat and pennyweight. The gram is the entry-level weight of a gold or silver bar. could more affordably purchase multiple bars from many different mints when choosing the one gram size. Convert between ounces and troy ounces with this conversion tool, data table and You can also convert between grams, pounds and ounces here. the avoirdupois ounce and troy ounce, see our post on how many ounces are in a pound. 30 Jan 2019 A troy ounce and an ounce are not equal to one another. Comparatively, whereas a traditional ounce weighs 28.3495231 grams, a troy ounce weighs ounce to a troy ounce, you want to multiple the Avoirdupois by 1.1. I knew that there was the difference but this cleared me up on the difference. Reply.