Work out how many revision sessions you can fit before an exam.
Counting revision sessions rather than days makes the plan concrete. Days divided by seven times sessions per week gives the sessions actually available, floored because a partial session does not count. Dividing by topics reveals whether each topic gets the two or three spaced passes that produce durable recall, or whether the plan only permits a single sweep — which is the point at which topics have to be prioritised.
Sessions available
Sessions = floor(days until exam / 7 x sessions per week)
Coverage per topic
Sessions per topic = sessions available / topics to revise
Two to three spaced passes is the usual target — an initial pass, a consolidation pass and a final practice pass. One pass produces recognition rather than recall.
Prioritise by exam marks available and current confidence. Attempting equal coverage of everything when time is short produces uniformly shallow preparation.