Path tracing is a well-known light transport algorithm used to render photo-realistic images. However, it is an expensive algorithm with an active area of research for improving its efficiency. In our work, we present a method to measure and visualize the regions of high computational cost for unidirectional path tracers. We have defined metrics to estimate the cost per pixel that can be visualized as a two-dimensional(2D) image. To show its usefulness, we present how our method can visualize the effect of changing material properties, object placement and other scene variables on computational cost. With this insight, the user can make clever choices to improve computational time.