Power-conversion efficiency is critical in power supplies. Switched inductors are popular in this space because they can deliver a large fraction of the power they draw. This fraction hinges on the power that switches, diodes, resistances, and capacitances need to conduct and transfer power to the output. So, understanding how these loss mechanisms set and dictate efficiency across power levels is important, especially when designing and targeting particular load levels. This article details how these losses scale, when they dominate, and how and when they balance. With this insight, predicting and controlling when efficiency rises, peaks, and falls across loads are possible. The fractional loss analysis and the design insight that make this possible are new contributions to the state of the art