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How Long Should You Really Study for an Exam?

  • Sean 

Knowing exactly how long you need to study for an exam can be difficult to judge. Luckily this article will tell all.

In general, try to spread 10-15 hours over 7-10 days when preparing for your upcoming exam. However, keep in mind that these are not hard rules. Both the hours and the number of needed days will depend on the volume and difficulty of the course material.

This article will delve separately into both how many hours and days you should be studying for an exam and the different factors to consider when planning out your revision. Finally, I will discuss why cramming isn’t actually such a bad alternative to this.

How Many Hours Should You Study for an Exam?

Generally, about 10-15 hours of high-quality studying is enough time to study for your upcoming exam. But this rule is not fixed. It depends on how much content is on the test, how difficult you find that content, and the techniques you use to learn that material. This range is just a starting point and could be much higher, or much lower.

This range is based on real data. This is roughly the amount of time I naturally tend to log when I am studying for an exam or midterm and I don’t cram for it.

Here is an example screenshot of my studying time one week leading up to a biology exam.

I got this number by taking the average amount of time I spent studying for 4 exams within the last year and I got an average of 14 hours and 43 minutes time studying the week leading up to the exam.

However, your range will depend significantly on how difficult you subjectively find the material, as well as how much material the exam covers.

I have also spent much less time than 15 hours preparing for an exam if there is just less content or I am already confident with the material (this is why the range starts at 10 hours).

However, the way that you use this time is also crucial to discuss.

What should you do during this time?

You can very easily waste these hours if they are not used efficiently.

These 10-15 hours need to consist of high-quality studying. This means using relatively more effective techniques than what most students traditionally rely on. In the example screenshot above I mostly relied on mind mapping and teaching the material out loud to myself. I only used a handful of flashcards to memorize some remaining details.

Some popular techniques would require much more time to get the same effect. You might be tempted to just rely on flashcards, but this would be an inefficient approach. I have a whole other article that explains how you should be using flashcards and why they should not be your main revision tactic.

Now that you know how many hours to study and roughly what to do during those hours, let’s go into how you many days you should spread them out over.

How Many Days Do You Need to Study for an Exam?

It depends, but in general, start studying 7-10 days before an exam. For a regular university or college exam, this is plenty of time. Having 7-10 days allows you to assess how long you should need exactly without ending up with too little time.

This starting point allows you to assess the difficulty of the material. If your upcoming exam is going to be hard, then you might need to use all 7-10 days.

On the other hand, maybe you find that you are very confident with the material and you don’t need nearly as much time. But be careful with how you determine your readiness. It is so easy to trick ourselves into thinking we know something when we really don’t.

This is especially true if you are assessing your exam readiness with the wrong techniques (rereading notes/textbooks etc).

If you want to really know that you are confident about your upcoming exam, I have another article that describes the 5 key signs that you are ready for an exam. If you have what that article talks about, you are definitely ready.

With that aside, let’s get into why spacing your time like this makes sense.

Space your studying time

Having this many days allows you to spread the needed 10-15 hours over many days rather than a few.

Ideally, you should be studying by distributing your time over many days rather than massing it in a short period of time because you will retain much more information. The research is pretty clear on this.1

By distributing your studying time in this way, you only need to study for a couple of hours a day.

However as you can see from my studying log above, you don’t even have to study for your exam every day. In fact, leaving some days blank is actually an opportunity to practice some spaced repetition.

To practice spaced repetition you space out your revision of the material. When you space your learning like this you will actually strengthen that information once you recall it again without looking at your notes, etc.

However, there is a drastic alternative to the approach that I have just described that is extremely common among students. What if you just left everything till the last minute? Can you actually be successful in this way?

Should You Cram for an Exam?

Cramming for an exam is common. About 49% of students admitted to cramming in a survey, meaning that they did not study throughout the term but only studied for their exams.2 Further, most students think that cramming works but the research says otherwise.3

First of all, this may surprise you given what I have said earlier, but I’m not going to come straight out against cramming. There is some benefit to this approach if it is done correctly (which it isn’t in most cases).

Cramming forces you to focus and cover a lot of material in a short amount of time. The mindset behind cramming, covering lots of material in little time, is generally a good one.

While ideally, you would just do this without the pressure of an upcoming exam, this doesn’t happen for most people because the time pressure is what makes it possible.

I will say that, Ideally, you should not be cramming. Cramming basically just gives you less time to do the same things. If you don’t cram and are disciplined with your time, you will have more time to use the exact same techniques and probably better.

But realistically most students will find themselves needing to cram at some point and it can be done relatively effectively.

Can you effectively cram for an exam?

So, if you find yourself needing to cram for an exam, as most students do, is there a good way to go about it?

It’s really going to depend on how you are cramming. If you just open one lecture at a time, try to learn everything in that lecture, and then move on to the next one, cramming will not work for you.

But there is a way to make cramming work.

If you are going to cram you need to prioritize the information. Finding the central concepts that, if learned, lead to a better understanding of the material as a whole. If you learn these pieces of high-yield information you can effectively piece together the right answer without having a complete understanding of the topic (which you will not get from traditional cramming).

If you want to learn more about cramming, check out my guide on how to cram for an exam in just 24 hours. In this guide, I describe exactly how I find this high-yield information and learn more in less time.

The Takeaway

Knowing how much time you need to study for an exam and how many days in advance to start studying can be difficult to judge. However, as a general rule, try to aim for 10-15 hours of high-quality studying over 7-10 days.

Also, remember to use effective study techniques during this time.

While it is generally recommended to spread out your studying time, there may be situations where you need to cram for an exam due to unexpected circumstances or a lack of time.

In these cases, it is important to prioritize the information into the key components that allow you to make good educated guesses at the rest of the material and not get bogged down in the details.


  1. Grote, M. G. (1995). Distributed Versus Massed Practice in High School Physics. School Science and Mathematics, 95(2), 97–101.
  2. Michaels, J. W., & Miethe, T. D. (1989). Academic Effort and College Grades. Social Forces, 68(1), 309–319.
  3. McIntyre, S. H., & Munson, J. M. (2008). Exploring Cramming: Student Behaviors, Beliefs, and Learning Retention in the Principles of Marketing Course. Journal of Marketing Education, 30(3), 226–243.