The Japanese Number System

Before we go much further, let’s go through the Japanese number system, starting with 1-10.

Number	Kanji	Hiragana
1	一	いち
2	二	に
3	三	さん
4	四	よん、し
5	五	ご
6	六	ろく
7	七	なな、しち
8	八	はち
9	九	きゅう
10	十	じゅう

Note that the pronunciations for “four” and “seven” can change, although the pronunciations in bold in the table are the most commonly used.

The numbering system in Japanese is “mathematical” in the sense that you talk in terms of multiples and additions. For the “teens” we talk in terms of addition only. For example, to say 13 you just say “10 3” (10 + 3).

Number	Kanji	Hiragana
11	十一	じゅう・いち
12	十二	じゅう・に
13	十三	じゅう・さん
14	十四	じゅう・よん
15	十五	じゅう・ご
16	十六	じゅう・ろく
17	十七	じゅう・なな
18	十八	じゅう・はち
19	十九	じゅう・きゅう

Beyond 19 we start talking in terms of multiples and additions. For example, to say 28 we say “2 10 8” (2 x 10 + 8). Using this logic we can get all the way to 99. A few examples:

Number	Calculation	Hiragana
43	(4 x 10) + 3	よん・じゅう・さん
67	(6 x 10) + 7	ろく・じゅう・なな
96	(9 x 10) + 6	きゅう・じゅう・ろく

Now you might be thinking 100 is simply “10 10”, but this would quickly get cumbersome as the numbers got larger. Instead additional words to signify larger milestone numbers are used.

Number	Kanji	Hiragana
100	百	ひゃく
1,000	千	せん

The logic, however, does not change. 229 is “2 100 2 10 9”.

229 = (2 x 100) + (2 x 10) + 9

Another example:

2,488 = (2 x 1,000) + (4 x 100) + (8 x 10) + 8

As you can see from the hiragana in bold in the table below, the readings can change depending on the combination. This is true for 100 and 1,000 multiples of 1, 3, 6, and 8.

Number	Kanji	Hiragana
300	三百	さんびゃく
600	六百	ろっぴゃく
800	八百	はっぴゃく
1,000	一千	いっせん
3,000	三千	さんぜん
8,000	八千	はっせん

As a general rule (not only applicable for numbers), when joining two kanji results in the following combinations, a bridging っ replaces the last syllable of the preceding kanji, and sometimes a dakuten or handakuten is added to the first syllable of the succeeding character.

• う + は
• つ + し
• ち + ひ
• く + か
• く + こ
• ん + a-ending syllable (only dakuten or handakuten added)

Take the word “school”, for example. Individually, the two kanji that make up the word for school have the following readings:

学 = がく

校 = こう

But when put together, the reading becomes:

学校 = がっこう

Indeed, this is actually a lot easier to pronounce (try repeating がくこう at any speed).

This bridging っ is called a sokuon (促音) and the process of changing the pronunciation of the following syllable is called rendaku (連濁). The rules for the rendaku are somewhat complex, such that beginners are better off making themselves aware of the basic rules above and picking up the exceptions along the way.

Back to our number system. Beyond 9,999 things start to change. The logic of multiples and additions still applies—the issue is that different numerical groupings are used. In Japanese there is no specific word for “million” or “billion”; instead you count things in terms of tens of thousands and one-hundred millions. Whenever you are weighing up the cost of bigger things (televisions, flights, hotels, etc.), you think of the price in terms of how many tens of thousands of yen. You will come across the counter for 10,000 (万, man) every day in Japan, and after a while you’ll be so used to it that if someone tells you (in English) that something costs ¥110,000 you’ll find yourself converting that back into the Japanese way of counting (i.e. ¥11,0000) in your head.

Number	Kanji	Hiragana
10,000	万	まん
100,000,000	億	おく

Admittedly, at first at least, this is a bit confusing because as English speakers we instinctively want to say “10 1,000” for 10,000. So following this Japanese logic, the number 689,614 breaks down as follows.

689,614 = (68 x 10,000) + (9 x 1,000) + (6 x 100) + 10 + 4

It may help to move the comma one place to the left when thinking about larger numbers, e.g. 689,614 = 68,9614.

Number	Hiragana
16,700	いち・まん・ろく・せん・なな・ひゃく
90,001	きゅう・まん・いち
200,200,200	に・おく・に・じゅう・まん・に・ひゃく