Plan revision backwards from the deadline

A revision timetable is a scheduling problem, not a study technique. It answers one question: given the days that actually remain and the hours you can actually sit down for, how many sessions does each topic get?

This post is only about that arithmetic. It makes no claim about grades, recall or any outcome, because a timetable cannot make one.

Work backwards, not forwards

Plan forwards and you start with topic one, spend as long as it takes, and discover in the last week that four topics are untouched. The deadline is the fixed point, so start there and count back.

Three numbers come out of counting back, in this order.

1. Days available. Not calendar days — days you will genuinely work. Take out the ones already spoken for.
2. A buffer. Reserve the last day for review of material you have already covered, not new material. Something always overruns, and a plan with no slack converts a single bad day into a failed plan.
3. Sessions per day. Hours you can sit down for, divided by session length, rounded down. A part session is not a session.

The worked example

Thirteen days until the exam. Two hours a day. Forty-five-minute sessions.

• Study days: 13 − 1 = 12, because the last day is review.
• Sessions per day: 120 ÷ 45 = 2.67, rounded down to 2. Three sessions would need 135 minutes and you have 120.
• Total sessions: 12 × 2 = 24.

Notice the slack this creates. Two sessions is 2 × 45 = 90 minutes, so 120 − 90 = 30 minutes a day is unscheduled. Check the whole run adds up: scheduled time is 24 × 45 = 1080 minutes, or 18 hours; unscheduled is 12 × 30 = 360 minutes, or 6 hours; and 18 + 6 = 24 hours, which is 12 × 2. It reconciles.

Dividing the sessions, and the remainder

Five topics, all treated the same. 24 ÷ 5 = 4 remainder 4.

The two tempting shortcuts are both wrong. Round every share up to five and you have promised 5 × 5 = 25 sessions when only 24 exist. Round every share down to four and 5 × 4 = 20, leaving four sessions unassigned, which in practice means they get absorbed by whichever topic you happen to be sitting in front of.

Do it properly: give every topic the floor, then hand out the remainder one session at a time. Four topics get 5, one topic gets 4. Check: (4 × 5) + 4 = 20 + 4 = 24. Exact.

Deciding which topic takes the short straw is the only judgement call in the whole method, and it belongs to you.

Weighting instead of splitting evenly

If some topics need more time, give each a weight and split in proportion. Three topics weighted 3, 2 and 1 have a total weight of 3 + 2 + 1 = 6, so with the same 24 sessions:

• 24 × 3 ÷ 6 = 12 sessions
• 24 × 2 ÷ 6 = 8 sessions
• 24 × 1 ÷ 6 = 4 sessions

Check: 12 + 8 + 4 = 24. When the weights do not divide the total evenly you are back to floors and a remainder, handled the same way.

Spread, do not block

Having decided the counts, spread each topic across the whole run rather than giving it one solid day. Coming back to something more than once is a scheduling convention worth following; no research finding is being cited for it here, and none is needed to see that a topic touched on day two and never again is a topic you will have to relearn.

The tool

The Study & Revision Planner does this division for you. List the subjects, optionally weight them one to five, give the days remaining, the hours a day and the session length, and it prints a day-by-day timetable that interleaves subjects rather than blocking them, pencils in a revisit of each subject roughly one, three and seven days after you first touch it, and leaves the final day for review.

It ends with a session count and an hour count per subject so you can check the totals yourself. If your list does not fit in the time you have, it says so plainly — including naming any subject that ended up with no sessions at all, rather than pretending the plan works.