Ounces to Carats

Ounce

An ounce (oz) is a small US customary unit of weight equal to 1/16 of a pound, or about 28.35 grams. It is commonly used in cooking, portion sizes, mail weighing, and food packaging. Ounces provide a practical scale for items too small for pounds but too large for grams alone.

Although the same word, ounce, also refers to a liquid measurement (fluid ounce), the two units are completely different. This converter focuses on ounces used for weight.

Carat

A carat (ct) is a specialized metric unit used to measure gemstones and pearls. One carat equals 200 milligrams — or 0.2 grams — making it perfectly sized for tiny but valuable items. Jewelers and gemologists rely on carats because small weight differences can significantly affect a stone’s price and quality.

Carats provide precision without using long decimal values in grams or milligrams. However, when converting gemstone weights to more common units, exact conversion factors are necessary — and this is where a converter becomes helpful.