How to Cram for an Exam: What the Research Says Works (2026)

The short answer. If the exam is days away, four things matter: test yourself instead of rereading, space your reviews even when the gaps are only a day, skip what you already know, and sleep the night before. Below is the research behind those four, and a plan for 72 hours, 48 hours and the last night. The examples are licensing exams (NCLEX, TEAS, HESI A2, SIE, real estate, CCMA), but the mechanics are the same for any test.

Why the all-nighter backfires

Memory consolidation happens substantially during sleep; Diekelmann and Born’s review (2010) lays out how sleep after learning stabilizes and reorganizes new memories (Nature Reviews Neuroscience). An all-nighter does two things at once: it removes the consolidation window for everything you studied, and it degrades recall and judgment on test day. On exams that score prioritization (the NCLEX, the suitability items on the Series exams), degraded judgment is the expensive half. The extra hours rarely buy what the lost sleep costs.

What works when time is short

• Retrieval practice. Testing yourself beats rereading for long-term retention: in Roediger and Karpicke (2006), students who took practice tests retained more a week later than students who restudied (Psychological Science). With days left, every session should be questions first, review second.
• Pretesting. Guessing before you study, even guessing wrong, improves learning of the answer: Richland, Kornell and Kao (2009, J. Exp. Psychol.: Applied) and Kornell, Hays and Bjork (2009, J. Exp. Psychol.: LMC). It also tells you what to skip, which in a cram is the biggest time saver available.
• Compressed spacing. Spaced study beats massed study across hundreds of experiments (Cepeda et al., 2006, Psychological Bulletin), and the follow-up found that the best gap between reviews grows with how far away the test is (Cepeda et al., 2008, Psychological Science). The rule of thumb for a short runway: a test in two weeks wants reviews a day to a few days apart, not a week. Review today’s material tomorrow, again a few days later, and once more before the exam.
• Interleaving. Mixing topics within a session, rather than blocking them, improved later test performance in Rohrer and Taylor (2007, Instructional Science). It trains you to recognize which idea a question is really testing, which is what mixed exams demand.
• Confident errors first. Errors made with high confidence are the ones most reliably corrected once you learn the right answer, the hypercorrection effect: Butterfield and Metcalfe (2001, J. Exp. Psychol.: LMC). When triaging, the things you were sure about and got wrong are the highest-value items on your list.

The plan

• 72 hours out. Diagnostic across the whole exam, questions before any reading. Rank topics by exam weight times your gap. Study the top of that list in short blocks, each block ending in questions. Review today’s misses before bed. Sleep normally.
• 48 hours out. Morning: yesterday’s misses first. Then the next tier of topics, mixed rather than blocked. One timed set in the afternoon for pacing. Evening: light review of confident errors. Sleep normally.
• The night before. Light review of the weakest items only. Nothing new: new material the night before displaces what you’d otherwise keep. Logistics checked. Normal bedtime.
• Exam-day morning. Ten minutes on your weakest items, then stop. Eat. Arrive early. Don’t open anything new.

What not to do

Reread or highlight (recognition, not recall) · study new material the night before · pull an all-nighter · spend long sessions on what you already know · block one topic for hours when the exam will mix them.

By exam

NCLEX in 2 weeks · TEAS in 2 weeks · HESI A2 in 2 weeks · SIE in 2 weeks. The full-runway versions: NCLEX, TEAS, SIE, Series 7, Series 65, Series 79 and CCMA study plans.

Trelos runs this method for you: it quizzes you before each lesson and skips what you already know, re-teaches confident misses first, and brings every concept back about 1, 3 and 7 days after you learn it. Every exam’s first topics are free with no sign-up to start.

Free to start, no sign-up.

FAQ

Is cramming ever effective?

Compressed, yes, if it’s retrieval-based, spaced even by a day, and followed by sleep. Massed rereading the night before is the version the research finds least effective.

How many days do I need?

Enough to review each important item at least twice with a gap between: with two weeks, reviews a day to a few days apart; with 72 hours, today, tomorrow, and exam morning.

Should I study the morning of the exam?

Briefly: ten minutes on your weakest items, nothing new.

Is it better to sleep or study one more hour?

Sleep. Consolidation after learning is where the hour’s studying gets kept.

Does this work for licensing exams specifically?

The studies above span vocabulary, facts, math problems and general knowledge; licensing exams test exactly those kinds of memory under time pressure.

Related: How Trelos works · NCLEX Study Plan · SIE Study Plan

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