The Weisskopfian approach has dominated empirical studies of the US rate of profit for the last thirty-five years. Forty-five years earlier, Michal Kalecki developed a different frame suitable for empirical profit rate studies, which had the potential to give different, but complementary, insight into the profit rate analysis based on the Weisskopfian approach. This paper first presents a development of the Kaleckian frame. It then applies this frame to the US economy and presents some preliminary empirical results.