The Hosokawa powder tester has been used for years to determine cohesion of bulk powders, including toner. For the first time a method is demonstrated to measure cohesive force distributions, rather than just average values, using the Hosokawa tester. The method is demonstrated for toner, varying surface additive composition and loading. Force distributions are shown to be generally log-normal. Both the mean and width of the distributions generally decrease with increased surface additive loading. Thus, better flow with additives decreases peak cohesion and distribution width.