There are many thousands of kanji in existence, but for practical purposes learning 2000 high frequency kanji will cover 99% of kanji encountered when reading in Japanese. Targeting to learn this many kanji is a good goal. This is certainly a tall order, and the question becomes how long it will take to learn them all.
On average it will take 595 hours over 3.3 years to learn 2000 high frequency kanji, which includes learning meanings, readings, radicals and how to write them. This time will vary depending on the learner and their learning system. Once learned, consistent practice is needed to retain them.
The figures of 595 hours over 3.3 years assume you are learning 3 kanji per day and using a spaced repetition system (SRS) to settle them into long-term memory. In an SRS, kanji are initially learned and then reviewed at frequent intervals. At first, review intervals will be on back-to-back days, then as time progresses, they will become further and further apart, that is, days to weeks to months.
The SRS used as the basis to calculate the number of hours and overall timespan to learn 2000 kanji was derived from a wonderful kanji learning service called WaniKani [1]. In this calculation, to learn a single kanji, the SRS has 11 intervals. The kanji is reviewed at the end of each interval. The durations of the first six intervals are all 1 day. The subsequent interval durations are shown in the table below.
| Interval | Duration in days | Cumulative days |
| 1 | 1 | 1 |
| 2 | 1 | 2 |
| 3 | 1 | 3 |
| 4 | 1 | 4 |
| 5 | 1 | 5 |
| 6 | 1 | 6 |
| 7 | 2 | 8 |
| 8 | 7 | 15 |
| 9 | 14 | 29 |
| 10 | 30 | 59 |
| 11 | 120 | 179 |
The following is a brief summary on how to learn a kanji, but for full details, I have written about all the strategies and entire process for learning kanji here. Learning a kanji is done in two steps: encoding and retrieval practice. Encoding is where you use a memory technique, such as a mnemonic, to tether the kanji you are learning to something you already know which facilitates recall.
Retrieval practice means retrieving a kanji from your memory in two ways: by recognizing it visually and successfully recalling its meaning and reading, and by seeing its meaning and successfully being able to write it and recalling its reading. In a world where we type more than handwrite, you could get away with not being able to write kanji, but for more well-rounded mastery, writing ability is still important.
It was using these two learning steps that I was able to make a calculation of the total time for learning kanji. Over the course of many kanji study sessions, I timed myself on how long it takes to encode new kanji and how long it takes to review learned kanji. Below are my actual measured time values.
For visual recognition and written production of a kanji, on average it takes:
- 4 minutes 42 seconds to encode one new kanji
- 32 seconds to review one kanji
Encoding (learning a kanji for the first time), is done in the first SRS interval. Review (retrieval practice) is carried out in subsequent intervals. One thing to point out here is that, in my own study sessions I found that right at the start of the learning process, I partially forget or make a mistake with almost 100% of the new kanji I am learning on the second day when writing them.
Before letting myself move on to further SRS stages, I want to be sure that I can successfully recall a kanji for four consecutive days. What this does in essence is it adds two days in front of the four successful recall days. In other words, it takes two days to get a kanji encoded in my mind, and then on the third day, that’s when the SRS really starts.
With the above information, we can calculate the amount of time it will take to learn one single kanji. On average it will take just 9.5 minutes over the course of 6 months to learn one single kanji. Initial encoding will take 4.7 minutes over the course of one or two days but settling it into long-term memory requires additional review time using a spaced repetition system.
For learning the 2000 kanji you need for literacy in Japanese, I use the highly useful set of kanji taught in WaniKani [2]. At the time of writing there are actually 2074 kanji in the set. There are also an additional 485 sub-components (radicals). For the most part, kanji are made up of sub-components which are highly beneficial to learn on their own because they greatly facilitate learning whole kanji.
So, including components, the real number of characters to learn is 2559 (but there are some duplicates as some components are also whole kanji on their own). The data in the tables below show the spread of how long it will take to learn kanji given how many you learn per day and the amount of recall errors made.
Explanation of the data:
- Percentage of recall errors means the percentage of all 2559 characters that you end up making a mistake on. Either you forgot the character completely, partially (just the meaning or the sound), or made a mistake when writing. The key assumption is that you only forget a given kanji once, and it occurs at the very end of the SRS cycle, which prompts the cycle to repeat again entirely for that kanji.
- Total years to completion are how long it will take to get through all 2559 characters.
- Total study hours are the sum total of hours spent learning, spread out over the course of the total years to completion.
- Max. average minutes of study per day are the average number of minutes of study per day during the height of your studies. There will be a very long period, starting after almost one year of study, that you will consistently be reviewing a high number of kanji per day.
- Max. number of kanji reviewed per day are the highest number of reviews (including new kanji being learned) that occur during the height of your studies.
1 kanji per day
| Percentage of recall errors | 0% | 25% | 50% | 75% | 100% |
| Total years to completion | 7.5 | 8.0 | 8.0 | 8.0 | 8.0 |
| Total study hours | 403 | 499 | 596 | 693 | 789 |
| Max. average minutes of study per day | 9 | 12 | 14 | 16 | 19 |
| Max. number of kanji reviewed per day | 11 | 15 | 17 | 20 | 22 |
2 kanji per day
| Percentage of recall errors | 0% | 25% | 50% | 75% | 100% |
| Total years to completion | 4.0 | 4.5 | 4.5 | 4.5 | 4.5 |
| Total study hours | 403 | 499 | 596 | 693 | 789 |
| Max. average minutes of study per day | 19 | 23 | 28 | 32 | 37 |
| Max. number of kanji reviewed per day | 22 | 30 | 34 | 40 | 44 |
3 kanji per day
| Percentage of recall errors | 0% | 25% | 50% | 75% | 100% |
| Total years to completion | 2.8 | 3.3 | 3.3 | 3.3 | 3.3 |
| Total study hours | 403 | 499 | 595 | 693 | 789 |
| Max. average minutes of study per day | 28 | 35 | 42 | 49 | 56 |
| Max. number of kanji reviewed per day | 33 | 45 | 51 | 60 | 66 |
4 kanji per day
| Percentage of recall errors | 0% | 25% | 50% | 75% | 100% |
| Total years to completion | 2.2 | 2.7 | 2.7 | 2.7 | 2.7 |
| Total study hours | 403 | 499 | 595 | 693 | 789 |
| Max. average minutes of study per day | 38 | 47 | 56 | 65 | 74 |
| Max. number of kanji reviewed per day | 44 | 60 | 68 | 80 | 88 |
5 kanji per day
| Percentage of recall errors | 0% | 25% | 50% | 75% | 100% |
| Total years to completion | 1.9 | 2.4 | 2.4 | 2.4 | 2.4 |
| Total study hours | 403 | 499 | 595 | 693 | 789 |
| Max. average minutes of study per day | 47 | 59 | 70 | 81 | 93 |
| Max. number of kanji reviewed per day | 55 | 75 | 85 | 100 | 110 |
How Many Kanji Should I Learn Per Day?
We can see that there is big difference between learning 1 vs. 5 kanji per day. There is a clear trade-off between the total years it will take, and the amount of study time needed per day. Overall, learning 3 kanji per day is a manageable number to aim for using a spaced repetition system. There will be variance in the total time to learn kanji based on the frequency of recall errors, but at 3 kanji per day the total time and daily time commitment is achievable.
I do 3 kanji per day in my own studies and find it to be manageable. In terms of error rate when doing reviews, I think you will find that you are pretty good at visually recognizing kanji and successfully recalling the meaning and reading, but it’s writing that is the real challenge. It is for me, and I find that a 50% error rate is representative of my own studies.
Further Considerations on the Calculation
I did this calculation to give people venturing into learning kanji a realistic expectation of the time commitment required. But for practical purposes some simplifying assumptions were made. One is that you only make a mistake or forget a given kanji at the very end of its SRS cycle, which initiates the cycle to repeat completely for that kanji. Allowances are not made for errors at other times during the cycle.
Another assumption is that you are doing recognition review and writing review simultaneously. If you do recognition review first, that is see a kanji and try to recall it’s meaning and reading, it takes away your ability to do spontaneous writing recall in which you would see the meaning first, then try to correctly write the kanji and recall its reading.
To overcome the above limitation, what I have done in my own studies is separate my recognition and writing practice. I did this inadvertently. I had been using WaniKani for about a year as my resource for initial visual encodings of kanji, their meanings and one of their readings, as well as an SRS for recognition review. But I was not learning how to write kanji.
To learn to write kanji, I put all the kanji and components into Anki flashcards and set the SRS settings to the timings shown above. Since I had such a big head start with WaniKani, I was able to get my recognition practice and writing practice onto separate timelines. This has the effect of increasing my total years to completion, but the total study hours remain the same.
Another limitation is that the calculation just shows the time it takes to learn individual kanji in isolation from one another. But of course, to really make use of kanji and be able to read in Japanese, you need to learn words that use the kanji, and also see those words in the context of sentences. This is called a contextual learning strategy, which I further explain in this article.
The great thing about WaniKani is that it does not just teach roughly 2000 kanji, it teaches about 6000 words that use the kanji as well, and provides several example sentences for each word. By this point you can probably tell that I really like WaniKani and highly recommend it!
How Long it Takes Natives to Learn Kanji and How They Do It
A good point of comparison is how long it takes Japanese students to learn kanji in school. Japanese students learn the 2136 jouyou kanji over the course of 12 years of study. Students learn to read and write the 1026 kyouiku kanji over 6 years in elementary school and by the end of high school they should be used to reading all the jouyou kanji and be able to write the main ones.
It is only the 1026 kyouiku kanji that are taught explicitly in a structured way over the 6 years of elementary school. Over the 3 years of junior high school, all or almost all the remaining 1110 kanji are learned, but the instruction method and how many kanji to be learned per year it is left to the individual schools. For example, in first year junior high school, students will learn 300 to 400 kanji [3].
By the end of junior high school, it is expected that students be able to write and use all kyouiku kanji in compositions, but as for the remaining kanji, it is only expected that they be able to read them. By the end of high school, although it is expected that students be able to write the main jouyou kanji, the Ministry of Education states that there is no requirement to able to handwrite them all [3].
Final thought. Even once you get through all your SRS and have the kanji in your mind, it is still so easy to forget them. Avid reading and typing are good ways to maintain your kanji recognition. But what will fade the quickest is your ability to handwrite. Advanced learners need to spend considerable time maintaining their kanji knowledge through continuous retrieval (writing) practice [4]. One of my middle aged native Japanese university professors said that she still practices writing kanji every Saturday.
So, in the end, the time it takes to learn kanji to achieve a high level of literacy in Japanese is finite. But the maintenance of your kanji skills is a lifelong journey. This is just one of the difficulties of kanji which you need to be prepared for; there are many more. For even more information about kanji, like how hard it is to learn, how to manage it, and why its actually useful, please have a look at my other articles linked below.
Even more articles about kanji!
- How to Learn Kanji: All the Strategies You Need and More!
- Learning Kanji is Doable, but the Struggle is Real
- If you Want to Learn Japanese, Learning Kanji is Essential
- Why Kanji is Used in Japanese and Why it Remains Important
- Jukugo 熟語: Super Words to Build Your Japanese Vocabulary
- Easy Ways to Read Kanji (lookup and identify any character)
References:
[1] WaniKani. (2023). WaniKani’s SRS Stages. WaniKani Knowledge Guide.
[2] WaniKani. (2023). What will WaniKani teach me?. WaniKani Knowledge Guide.
[3] 「常用漢字表改定に伴う学校教育上の対応について」（まとめ）. 平成２２年９月２９日. Ministry of Education, Culture, Sports, Science and Technology.
[4] Rose, Heath. (2017). The Japanese Writing System: Challenges, Strategies and Self-regulation for Learning Kanji. Multilingual Matters, Bristol, Blue Ridge Summit.