How long before an exam should I start revising?

For school tests, start about two weeks before. For term exams and board exams, start four to eight weeks before, with light weekly review through the whole year. Starting early lets you space out your revision, which helps you remember more for longer.

Is rereading my notes a good way to revise?

Rereading feels productive because the material looks familiar, but familiarity is not the same as being able to recall it in an exam. Use rereading only as a first step, then close the book and test yourself.

How many hours a day should I revise?

Quality matters more than hours. Two or three focused hours split into short sessions with breaks is usually better than six tired hours. In the final weeks before board exams, many students revise four to six hours on holidays, still in blocks with real breaks.

Study skills

How to revise for exams effectively, a guide for students

Revise smarter with spaced repetition and retrieval practice. Practical steps, a sample one-week plan and a checklist you can start using today.

For students. By the Qlive team. 1 September 2026 . 6 min read.

You have probably had this experience. You spend a whole evening reading a chapter, highlighting the important lines, and you feel ready. Then the test paper arrives and the answer you read three times simply will not come back. That does not mean you are bad at studying. It usually means you were revising in a way that feels good but does not build memory.

This guide explains two techniques that learning researchers have studied for decades, spaced repetition and retrieval practice, and shows you exactly how to use them for school exams.

Why rereading lets you down

When you reread notes, your brain recognises the words. Recognition feels like knowing. But an exam does not ask you to recognise. It asks you to produce the answer from memory, often in a slightly different form from your notes.

The fix is simple to say and a little harder to do: spend less time putting information in and more time pulling it out.

Technique 1: retrieval practice

Retrieval practice means testing yourself. Every time you force yourself to recall something without looking, you strengthen the path to that memory. It also shows you, honestly, what you do not know yet.

Ways to practise retrieval:

Blank page recall. Close your book. On a blank sheet, write everything you remember about a topic, for example “photosynthesis” or “causes of the First World War”. Then open the book and fill the gaps in a different colour pen.
Questions at the end of the chapter. Answer them without looking back. Mark yourself.
Flashcards. A question on one side, the answer on the other. Our guide on active recall and flashcards explains how to make good ones.
Past papers and sample papers. The closest thing to the real exam.
Teach it. Explain the topic aloud to a sibling, a parent or an empty chair. Where you stumble is where you need work.

Getting answers wrong during retrieval practice is useful. A mistake you catch at home is one you are less likely to make in the exam hall.

Technique 2: spaced repetition

If you revise a topic once, you will forget much of it within days. If you come back to it after a gap, recall it again, and then leave a longer gap before the next review, the memory becomes much more stable. That is spaced repetition.

A simple spacing pattern for school:

Review	When
First learning	Day 1 (in class or self-study)
Review 1	Day 2
Review 2	About 1 week later
Review 3	About 2 to 3 weeks later
Review 4	Just before the exam

Each review should be a retrieval review: test yourself first, then check. If you get everything right, the next gap can be longer. If you struggle, shorten the gap.

Spacing is the reason cramming the night before does not work well. Everything is packed into one session, so there is no time for forgetting and recalling, which is what makes memory last.

Mixing topics (interleaving)

When you practise maths, it is tempting to do twenty questions of the same type in a row. By question five you are just copying the pattern. In the exam, though, questions from different chapters come mixed together, and part of the skill is recognising which method to use.

Once you are comfortable with a topic, mix it up. Do a set of questions from three or four chapters together. It feels harder, and that is exactly why it helps.

A step-by-step revision method

Here is a routine you can use for any subject:

List the topics. Use your syllabus or the chapter list. Break big chapters into smaller topics.
Rate each topic. Green (confident), amber (partly), red (weak). Be honest.
Start with retrieval, not reading. Try a blank page recall or a few questions first. This tells you what to focus on.
Fill the gaps. Now read your notes or textbook, only for the parts you missed.
Test again. Close the book and recall once more.
Schedule the next review. Put the topic back in your plan for a few days later.
Practise exam-style questions. Especially for red and amber topics.
Keep a mistake notebook. Write every error you make, why it happened and the correct method. Review this notebook every week.

A sample one-week revision plan

This example is for a Grade 9 or 10 student with a school test in two weeks, revising about two hours on school days.

Day	Session 1 (45 min)	Session 2 (45 min)	Quick review (20 min)
Monday	Maths: quadratic equations, questions	Science: blank page recall, chemical reactions	Flashcards from last week
Tuesday	English: practise one long answer	Social Science: map work and key dates	Mistake notebook
Wednesday	Science: physics numericals	Maths: mixed questions from three chapters	Flashcards
Thursday	Social Science: blank page recall, one chapter	Second language: grammar exercises	Review Monday’s topics
Friday	Maths: past paper section, timed	Science: biology diagrams from memory	Flashcards
Saturday	Full timed sample paper in one subject	Mark it and correct mistakes	Free evening
Sunday	Rest	Plan next week using your red and amber list

Notice that every day includes a short review of older material. That is spacing in action.

Habits that make revision work better

Short sessions with breaks. Around 30 to 50 minutes of focus, then a 5 to 10 minute break away from your desk.
Phone in another room. Even a silent phone on the desk pulls at your attention.
Sleep. Your brain consolidates memories during sleep. Staying up late to revise often costs more than it gains.
Hardest subject when you are freshest. For most people that is earlier in the day.
Move your body. A walk or some exercise between sessions helps you focus again.

Revision checklist

Before an exam, check that you can say yes to these:

I have a list of every topic in the syllabus.
I know which topics are red, amber and green.
I have tested myself on every topic at least twice, with gaps in between.
I have done at least one timed past paper or sample paper.
I have a mistake notebook and I have reviewed it.
I have a plan for the last three days that is light, not a cram.

When you are stuck on the same topics

Sometimes the same red topics stay red no matter how much you revise. Often the real problem sits further back: a concept from an earlier grade that never quite clicked. Revision techniques cannot fix a gap you cannot see.

That is where a one-to-one teacher can help, working through the topic with you at your pace and building on what you already know. If you want to find out exactly what needs work, Qlive offers a free assessment that pinpoints your strong areas and specific gaps, so your revision time goes where it matters. You can read how Qlive classes work before you decide.