How to revise: the complete guide for any exam

Why most revision feels useless

Re-reading your notes feels productive. Highlighting whole paragraphs feels productive. Watching a YouTube revision video feels productive. Decades of cognitive-science research says none of it really is. They're all passive — your brain recognises the material but can't recall it under pressure.

Effective revision is active: you force your brain to retrieve information from scratch, then space those retrievals out over time. That's it. Everything else is window dressing.

The two techniques that actually work

1. Active recall

Instead of reading a topic, close the book and try to write down or say out loud everything you know about it. Then check what you missed. Repeat. Each retrieval makes the memory stronger and easier to access in the exam.

Practical ways to do active recall:

• Past paper questions (the gold standard)
• Flashcards (Anki, Quizlet, or paper)
• Blurting: write everything you remember about a topic on a blank page
• Teaching the topic to someone else (or to your wall)

2. Spaced repetition

Review material at expanding intervals: 1 day, 3 days, 1 week, 2 weeks, 1 month. The forgetting curve is steep, but each well-timed review flattens it dramatically. Read our guide to spaced repetition for the full breakdown.

How to plan your revision

Don't build a colour-coded hour-by-hour timetable. They look great for three days and then fall apart the moment life happens. Instead:

1. List every topic on every spec for every subject. This alone is more useful than most people realise.
2. Rate each topic red / amber / green based on how confident you are right now.
3. Block your week into 2–3 hour study sessions, and at the start of each session pick the next red topic.
4. Track hours per subject so you don't accidentally over-revise the one you enjoy and ignore the one you fear. The free study diary handles this automatically.

Need a starting point? Use our free revision timetable generator — answer four questions and you'll get a realistic weekly plan.

How many hours should you revise?

A useful rule of thumb for serious exams (GCSE, A-Level, IB, university finals):

• Roughly 100 hours per exam subject across the whole revision period. Some subjects need more, some less, but 100 is a sane baseline.
• 3–5 hours per day of genuinely focused revision is more sustainable and effective than 8-hour grinds.
• Track real focus, not bum-on-seat time. Two focused hours beats five distracted hours every time.

The Pomodoro technique (optional but useful)

25 minutes of work, 5 minutes break, repeat. After four rounds, take a longer break. It's not magic — it just stops you from burning out and gives you permission to rest. See our full Pomodoro guide for variations that actually work for revision.

Common revision mistakes to avoid

• Re-reading instead of testing. If you can't close the book and explain the topic, you don't know it yet.
• Making notes from textbooks. You're just copying. Make notes from memory, then check.
• Cramming. One night of cramming is worth maybe a third of the same hours spread across two weeks.
• Studying everything at once. Single-topic focus blocks beat constant subject-switching.
• Ignoring sleep and exercise. Both massively boost memory consolidation. Skipping them is self-sabotage.

FAQs

How many hours a day should I revise?

3–5 hours of focused revision per day in the final weeks before exams is the sustainable sweet spot. Quality of focus matters more than total hours.

When should I start revising?

For GCSE and A-Level, start structured topic-by-topic revision 8–12 weeks before your first exam. For university finals, 4–6 weeks is usually enough if you have good notes.

What's the single best revision technique?

Active recall combined with spaced repetition. Everything else is secondary.