Abstract: The present disclosure is directed towards methods of making titanium diboride products in various sizes. An aspect of the method provides (a) selecting a target average particle size for a target titanium diboride product; (b) selecting at least one processing variable from the group consisting of: an amount of sulfur, an inert gas flow rate, a soak time, and a reaction temperature; (c) selecting a condition of the processing variable based upon the target average particle size; and (d) producing an actual titanium diboride product having an actual average particle size using the at least one processing variable, wherein due to the at least one processing variable, the actual average particle size corresponds to the target average particle size.