# Understanding Japanese Numbers to Unlock Your Hidden Potential

Japanese numbers are a bit complicated. Learning numbers in any language (even one’s mother tongue) is always somewhat difficult, but learning Japanese numbers in particular has some extra complexities.

For starters:

Did you know the number 100,000 is called “ten ten thousand” in Japanese?

Did you know that “1 million” is called “1 hundred ten thousand” in Japanese?

These and other fundamental differences in how Japanese conceives numbers add to the already difficult task of learning numbers in a foreign language.

But don’t fret! In this article, I will give you a detailed introduction to how Japanese numbers work.

After reading this article, you will not only know how to read Japanese numbers, but you will also start thinking about numbers the way the Japanese language does.

This will allow you to translate between an English mentality and a Japanese one.

But before we get into any theory, let me give you the names of Japanese numbers 0–10.

We’ll talk about them later in more depth, but I want to give you their names up front so you can start to get a feel for Japanese numbers:

0 = rei

1 = ichi
2 = ni
3 = san
4 = yon/shi
5 = go
6 = roku
7 = nana/shichi
8 = hachi
9 = ku/kyū

10 =

To understand the names of all other Japanese numbers, though, we need to get into a bit of theory. We won’t get into any arithmetic (sum, difference, multiplication, division), so don’t worry if you hate math!

We will start with some basic mathematics concepts, but I promise they won’t be too difficult. Plus we’ll discuss Japanese numbers all the way to 1 trillion, so it’ll all be worth it.

So let’s get to it! To learn how Japanese numbers work, we first need to talk a little about the number 10.

Note: If you’re just beginning to learn Japanese and are looking for a guide on getting started, check out my list of 5 resources for learning Japanese.

## Powers of 10

The number ten is very important to humans. Since most humans have ten fingers, the number ten is a pretty natural benchmark for counting. Notice how we have ten digits:

0  1  2  3  4  5  6  7  8  9

If you count from 0 to 9, you only need a single digit to represent all the numbers in the sequence. But what happens when you need to write the number ten?

10

We run out of single digits, so we add a new second digit to the left, make that digit 1 and reset the first digit to 0. After that, the numbers 11 through 19 simply change one digit (the first digit):

11   12   13   14   15   16   17   18   19

And what happens when we get to twenty?

20

We run out of digits again for the first digit, so we increase the second digit to 2 and again reset the first digit to 0. This pattern continues all the way to 99:

0 .. 9

10 .. 19

20 .. 29

30 .. 39

40 .. 49

50 .. 59

60 .. 69

70 .. 79

80 .. 89

90 .. 99

What happens when we get to one hundred?

100

We run out of digits for both digits, so we add a new third digit to the left, set that digit to 1 and reset the others to 0.

Then we can express all numbers from 101 to 999, until we get to one thousand, where we have to add yet another digit: 1,000.

With that, we can get all the way to 9,999 and then, for the number ten thousand, we again add another digit: 10,000.

This pattern of adding a new digit to the left set to 1 and resetting the rest to 0 continues to infinity.

These numbers made up of a 1 followed by any number of 0s are special to humans. These numbers are called powers of 10.

10 = ten

100 = one hundred

1,000 = one thousand

10,000 = ten thousand

100,000 = one hundred thousand

1,000,000 = one million

10,000,000 = ten million

100,000,000 = one hundred million

1,000,000,000 = one billion

Notice the English names for these numbers.

English has unique names for the numbers 10 (ten), 100 (hundred) and 1,000 (thousand), but, starting with 10,000, English starts combining the names of previous powers of 10 to make new names: ten thousand.

This continues with 100,000 (hundred thousand), and then—for 1,000,000—English adds a new unique name: million.

Then English again combines previous names for the next powers of 10 (ten million and hundred million) until the next unique name comes up, which is  “billion” for 1,000,000,000.

Japanese numbers work similarly to English numbers in that they are based on powers of 10 and follow a very regular pattern.

However, there is one seemingly small difference that makes everything complicated.

## Oh, Man (10,000)

We saw that English has unique names for the powers of 10 that have one zero (ten), two zeros (hundred), and three zeros (thousand).

Starting with 10,000 (ten thousand), however, English starts combining the names of previous powers of 10 to make new ones.

But, why stop giving unique names after just three zeros? Is there any special reason for that? Well, Japanese doesn’t seem to think so.

### Japanese Numbers from 0 to 10

First, let’s name the ten Japanese digits.

Japanese actually has two names for certain numbers: a Japanese name and a Chinese name.

The Japanese names are usually only used with really small quantities or in very specific contexts, so we won’t discuss them in this article.

In this article, we’ll mostly focus on the Chinese name (and on a few exceptions where the Japanese name is used) since these are the names used for all numbers all the way to infinity.

The names for the ten Japanese digits are:

0 = rei*
1 = ichi
2 = ni
3 = san
4 = yon*/shi
5 = go
6 = roku
7 = nana*/shichi
8 = hachi
9 = ku/kyū

*These are Japanese names, but are commonly used.

After the ten digits, we have our first power of 10:

10 =

Apart from how to read the number 10 (), you should also know the kanji for it, which is 十.

Don’t get scared by the kanji! I’ll only use the kanji for powers of 10 because they’re important and commonly used in the real world.

### The Japanese Number Naming Pattern

From 11 to 19, the names of Japanese numbers follow a regular pattern made up of followed by the name of the the first digit:

11 = jūichi
12 = jūni
13 = jūsan
14 = jūyon
15 = jūgo
16 = jūroku
17 = jūnana
18 = jūhachi
19 = jūkyū

So the numbers from 11 to 19 are literally called: “ten-one,” “ten-two,” “ten-three,” “ten-four,” and so on.

For 20, we simply add the name for 2 (ni) in front of the name for 10 () to get nijū. So, in Japanese, 20 is literally called “two-ten”. After that, the numbers 21 through 29 simply combine nijū with the name of the first digit:

21 = nijūichi
22 = nijūni
23 = nijūsan
24 = nijūyon
29 = nijūkyū

It’s a pretty regular pattern, right?

As you might have guessed, 30 is called sanjū (literally “three-ten”), and 31 is sanjūichi, 32 is sanjūni, 33 is sanjūsan, and so on and so forth. This naming pattern continues until 99, which is kyūjūkyū (literally, “nine-ten-nine”).

The number 100 is called hyaku and its kanji is 百.

After 100, the same pattern for numbers 0…99 is repeated just with hyaku in front:

101 (hyakuichi),
102 (hyakuni),
110 (hyakujū),
112 (hyakujūni),
120 (hyakunijū),
121 (hyakunijūichi),
130 (hyakusanjū),

and so on.

For 200, we simply add ni in front of hyaku: nihyaku, so 200 is literally called “two-hundred;” 300 is sanbyaku (the “h” sound in hyaku changes to a “b” sound after san). We this patter, we can name all numbers up to 999, which is kyūhyakukyūjūkyū (literally, “nine-hundred-nine-ten-nine”).

The number 1,000 is called sen and its kanji is 千.

After 1,000, the same pattern holds but now sen is placed in front:

1001 (senichi),
1002 (senni),
1011 (senjūichi),
1012 (senjūni),
1101 (senhyakuichi),
1111 (senhyakujūichi),
1212 (sennihyakujūni),
2321 (nisensanbyakunijūichi),
3958 (sansenkyūhyakugojūhachi),

and so on until 9,999 (kyūsenkyūhyakukyūjūkyū).

### Ten Thousand Breaks the Mold

The number 10,000 is where things get really interesting in Japanese.

As we know, in English, the number 10,000 is named combining the names of previous powers of 10: “ten thousand.”

Therefore, coming from an English mentality, you might expect that 10,000 would be called something like “jūsen.”

However, that’s actually not the case in Japanese. In Japanese, the number 10,000 has a unique name, just like 十, hyaku 百, and sen 千.

The number 10,000 is called man in Japanese and its kanji is 万.

This may not initially seem like much of a break from the English pattern, but, in reality, the fact that 10,000 has a unique name in Japanese makes the way Japanese thinks about numbers significantly different from English.

## Ten Thousand Is One Man

Let’s look again at the English powers of 10 up to 1 million:

10 = ten
100 = one hundred
1,000 = one thousand
10,000 = ten thousand
100,000 = one hundred thousand
1,000,000 = one million

In English, the powers of 10 have unique names for one zero (ten) up to three zeros (thousand) before repeating previous names.

In Japanese, the powers of 10 up to 10,000 are the following:

10 =
100 = hyaku
1,000 = sen
10,000 = man

What would 100,000 be called in Japanese? Well, after man, Japanese does like English and starts combining previous names of powers of 10 to make new names.

Let’s take a closer look at the English pattern for combining previous names of powers of 10.

In English, when we start repeating names with 10,000, we take the name for 10 (ten) and put it in front of the last unique name we used (thousand) to form “ten thousand.”

Japanese works in a similar way. To form the name for 100,000 in Japanese, we take the name for 10 () and place it in front of the last unique name we used (man).

This gives us:

100,000 = jūman

That’s right. The Japanese name for 100,000 translates to “ten ten thousand” in English.

When first starting to learn numbers in Japanese, this is terribly uncanny. We are used to calling 100,000 as “one hundred thousand” in English, but calling this number “hyakusen” would be incorrect in Japanese.

One way of wrapping your mind around this is to not think of 10,000 as “ten thousand,” but rather as “one man.”

With this little mental trick, we can adapt the English naming pattern for numbers to fit into the Japanese one:

10 = ten
100 = one hundred
1,000 = one thousand
10,000 = one man
100,000 = ten man

It’s still a bit uncanny, but this adaptation makes the Japanese name for 100,000 a little bit easier to understand from an English mentality.

For something we take so for granted as numbers, getting used to this way of thinking about them takes a lot of time, practice, and patience, but it’s definitely achievable. Just take it very slowly at first and never rush.

You can reread what we’ve discussed so far as much as you want before continuing.

### One Million in Japanese

Now that we’ve established how Japanese uses man, what would 1,000,000 be in Japanese?

We started repeating the names of powers of 10 with 100,000 and, for that number, we used the name for 10 () followed by man

That means that, for 1,000,000, we would have to use the name for 100 (hyaku) instead of and follow it by man:

1,000,000 = hyakuman

This means the Japanese name for 1,000,000 translates to “one hundred ten thousand” in English. You can also think of it as “one hundred man.”

The next power of 10 would be 10,000,000. Following the pattern, we would now have to use the name for 1,000 (sen), followed by man.

This gives us:

10,000,000 = senman

This means the Japanese name for 10,000,000 translates to “one thousand ten thousand” in English. You can also think of it as “one thousand man.”

The next power of 10 would be 100,000,000.

What happens then?

In English, after we’ve repeated the names “ten” and “hundred,” we don’t use “thousand” for 1,000,000 (we don’t call this number “one thousand thousand”) and instead introduce a new unique name: million.

Japanese works similarly.

After repeating , hyaku, and sen, we don’t not use man for 100,000,000 (we don’t call this number “manman”) and instead introduce a new name: oku, whose kanji is 億.

Thus:

100,000,000 = oku

This means that, similarly to how we can think of 10,000 as “one man,” we can think of 100,000,000 as “one oku.”

How’s everything so far?

Japanese numbers feel pretty uncanny at first, right? But at the same time it’s pretty similar to the English naming pattern.

If you can just manage to get used to using man, everything else will start to fall into place.

Let’s summarize the Japanese names of all the powers of 10 discussed so far before moving on to the next powers of 10:

10 =
100 = hyaku
1,000 = sen
10,000 = man
100,000 = jūman
1,000,000 = hyakuman
10,000,000 = senman
100,000,000 = oku

Seeing the powers of 10 this way makes the pattern clearer. It takes practice (and patience), but you’ll eventually get used to thinking about numbers the Japanese way.

### The Road to 1 Trillion in Japanese

The next power of 10 is 1,000,000,000.

In English, this number has already exhausted the names “ten” and “hundred” (because it’s the power of 10 that comes after “one hundred million”), and is thus given a new unique name: billion.

In Japanese, however, when we reach 1,000,000,000, we’ve only just introduced the unique name oku in the previous power of 10.

This means that we have no need for yet another unique name for this number: we simply use the name for 10 () followed by oku:

1,000,000,000 = jūoku

This means the Japanese name for 1,000,000,000 translates to “ten one hundred million” in English. You can also think of it as “ten oku.”

Can you guess the names of the next Japanese powers of 10?

10,000,000,000 = hyakuoku
100,000,000,000 = senoku

These names simply follow the pattern of using hyaku and sen in front of oku, respectively.

After that, Japanese adds another unique name for the next power of 10. The new name is chō and its kanji is 兆:

1,000,000,000,000 = chō

At first, it may seem a bit like overkill to learn how to express numbers up to 1 trillion in Japanese.

However, as we’ll see in the next section, what might look to us like really high numbers are actually quite commonplace in Japanese.

The next section presents some real-life examples of Japanese numbers (especially really large Japanese numbers).

If you want to review the theory we’ve discussed so far before moving on, feel free to do so as many times as you wish.

Again, it’ll take time, practice, and patience to get used to Japanese numbers, so don’t ever feel a need to rush through the process.

## The Yen and Japanese Instagram Followers

### The Yen

Let’s talk about the Japanese yen.

The yen (¥) is the Japanese currency. While the value of any given currency fluctuates wildly every day (and the pandemic has significantly changed currency dynamics), for many years the value of 1 yen has been rounded to approximately 0.01 US dollars.

¥1 ~ US \$0.01

This conversion has changed with the pandemic, but it’s still a useful (very) rough estimate, so we’ll use it for our examples.

Under this conversion, 1 yen is roughly equal to 1 cent of a US dollar. A nice trick to convert dollars into yen with this rough conversion is to add two 0s to the right of the US dollar amount.

With this (very) rough conversion between the two currencies, let’s try to find yen approximations to some US dollar amounts. Let’s start with \$100.

\$100 ~ ¥10,000

So 100 dollars is approximately 10,000 yen. In Japanese, this amount would be called either man 万 or ichiman 1万 (literally “one man“).

\$10,000 ~ ¥1,000,000

Look at that! We already made it to 1 million yen (called either hyakuman 百万 or ippyakuman 1百万 in Japanese)!

\$1,000,000 ~ ¥100,000,000 (ichioku 1億)

So we need to use oku 億 just to express an amount of yen equivalent to US \$1 million or greater.

During the height of the COVID pandemic, President Biden signed into law the American Rescue Plan, which distributed \$1.9 trillion in aid to Americans.

Don’t worry, we’re not even going to try to convert that into yen. However, we can try to translate that amount of dollars into Japanese:

1,900,000,000,000 = icchōkyūsenoku 1兆9千億

From our discussion in the previous section, we know one trillion is chō 兆 in Japanese and that one hundred billion is senoku 千億, so 1.9 trillion must be 1 chō 9 senoku or 1兆9千億.

These examples should demonstrate that knowing Japanese numbers up to 1 trillion isn’t some academic exercise.

Japanese handles really big numbers on a daily basis, especially because of the significant difference in value between the yen and the dollar.

You can expect to pay over ¥100,000 for one of the latest models.

Let’s now look at how Instagram followers are expressed in Japanese numbers.

This exercise will further show the usefulness of understanding big numbers in Japanese and of learning the kanji for Japanese powers of 10.

### Japanese Instagram Follower Count

Remember that I showed you the kanji for various powers of 10 and that I mentioned they’re used in the real world?

Well, one place they’re commonly used is in displaying Instagram follower counts.

Let’s look at a few real-world examples of how Instagram follower counts are displayed in Japanese. But first, I’ll sum up the kanji we’ve studied in this article for various powers of 10:

10 =

100 = hyaku

1,000 = sen

10,000 = man

100,000,000 = oku

1,000,000,000,000 = chō

Let’s look at our first Instragram follower count example:

The second column is the one indicating someone’s follower (フォロワー) count.

As we can see, Person 1 has 208.7万 followers. How many followers would that be in English?

Since this number is expressed in 万 (man), we know that the digit located just to the left of the decimal point (the 8) must be the one that corresponds to the 万 power of 10.

In other words, the 8 just to the left of the decimal point must be located where the 1 in 10,000 is located, that is, the fifth place. With that clue, we can expand the number like so:

2087000

And if we add commas every three digits, we get:

2,087,000

To produce this expansion, we removed the 万, moved the decimal point four places to the right (so the 8 will now be located in the fifth place) and added zeros to fill the places to the right of the 7.

With this expanded number, we see that 208.7万 translates as “2 million 87 thousand,” so Person 1 has over 2 million Instagram followers.

In case you’re wondering, in Japanese, the number 2,087,000 is read nihyakuhachimannanasen or 2百8万7千.

See how useful those kanji for powers of 10 are?

And if you’re wondering how to read 208.7万, it would be nihyakuhattennanaman (literally, “two hundred eight point seven ten thousand”). The decimal point is read ten in Japanese.

Whew, that was a bit of a mental workout, wasn’t it?

Not only did we have to think about a number expressed in 万, but we also added the complexity of the decimal point, which we hadn’t discussed until now.

Let’s look at another example:

With this user, we’ve gone up one power of 10 compared to the previous example. Person 2 has 1,189万 Instagram followers.

First, let’s expand that number, as we did for the previous example.

This time, there is no visible decimal point, so the point must be located in the rightmost spot of the entire number, that is, right after the 9. This means that the 9 must be in the fifth place:

11890000

If we add the commas, we get:

11,890,000

So 1,189万 translates in English to “11 million 890 thousand,” which means Person 2 has over 11 million Instagram followers.

In Japanese, the number 11,890,000 is read issenippyakuhachijūkyūman or 1千1百8十9万.

Since the number 1,189万 doesn’t have a visible decimal point, it is read exactly the same as 11,890,000.

Did that second example help make things clearer? I have one more example, but, don’t worry, this one is really simple.

This extremely famous user has 3億 Instagram followers. We already know that 億 means 100,000,000, so Person 3 has over 300,000,000 Instagram followers.

I hope these Instagram follower examples have demonstrated how useful and important the kanji for powers of 10 are for understanding Japanese numbers.

They also should serve to further demonstrate that learning how to express big Japanese numbers is an important skill for everyday Japanese.

## Conclusion

Understanding Japanese numbers is complicated when starting out from an English mindset.

Not only does one have to learn the names of the numbers, but one must also learn how to think about numbers the way Japanese does, which is different from the English way.

However, with a solid understanding of the powers of 10, getting used to using man 万 is possible with time and practice.

Once you manage to start thinking in terms of Japanese powers of 10 such as man 万 (10,000), sen 千 (1,000), hyaku 百 (100), and 十 (10), the rest will fall into place much more easily.

#### Before you go!

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## By José Carlos Bonilla

José Carlos Bonilla Martín is a professional Puerto Rican freelance translator. He holds an M.A. in Translation and a B.Sc. in Computer Science, both from the University of Puerto Rico. José Carlos is also an avid language learner and he has studied Japanese on his own since 2005. On his free time, he enjoys photography, a big cup of black coffee, reading Japanese comics (in Japanese), writing movie reviews, and baking cakes.