When presented with the choice to invest cognitive control in a task, several signals are monitored to reach a decision. Leading theoretical frameworks argued that the investment of cognitive control is determined by a cost-benefit computation. However, previous accounts remained silent on the potential role of subjective experience in this computation. We experience confidence when giving an answer, feel the excitement of an anticipated reward, and reflect on how much effort is required for successful task performance. Two questions are investigated in the present work: how objective task parameters give rise to subjective experience and whether these drive the decision to allocate cognitive control. To this end, we designed a task in which we manipulated three objective parameters in the same sequence of events (stimulus uncertainty, physical effort, and reward prediction error). We asked participants to report their subjective experiences associated with these manipulations: confidence, subjective physical effort, and reward satisfaction. At the end of each trial, participants indicated whether they wanted to repeat that trial on the next day. In response to the first question, we demonstrate that subjective ratings are reliable and selective. Subjective experiences closely mirrored their objective manipulations. In response to the second question, we demonstrate that subjective experiences provide a better fit for the decisions on future control investments. While objective task parameters are considered when deciding, they do not always produce the expected changes in subjective experience, and when dissociations occur, it is the subjective experience that better explains the decision to allocate cognitive control.