To enable teachers to set measurable and fair reading targets for graded reading, the author used average word counts from major publishers to develop a simple rule of thumb. As many have found, setting an appropriate reading target for an extensive reading programme is not as straightforward as it might seem. A number of complex issues, such as how much reading learners need, and at which levels, makes target setting difficult. In order to justify the proposed rule of thumb, this paper explores how much reading is necessary for learners to be successful. The focus is on suitable reading volume and reading level.