Japanese has two number systems - one borrowed from Chinese (on’yomi), one native Japanese (kun’yomi). You need both. The Chinese system handles most counting; the native system is used for counting small quantities of things.
Numbers 1-10: Both Systems
| Number | Kanji | Sino-Japanese | Native Japanese |
|---|---|---|---|
| 1 | 一 | いち (ichi) | ひとつ (hitotsu) |
| 2 | 二 | に (ni) | ふたつ (futatsu) |
| 3 | 三 | さん (san) | みっつ (mittsu) |
| 4 | 四 | し / よん (shi/yon) | よっつ (yottsu) |
| 5 | 五 | ご (go) | いつつ (itsutsu) |
| 6 | 六 | ろく (roku) | むっつ (muttsu) |
| 7 | 七 | しち / なな (shichi/nana) | ななつ (nanatsu) |
| 8 | 八 | はち (hachi) | やっつ (yattsu) |
| 9 | 九 | きゅう / く (kyuu/ku) | ここのつ (kokonotsu) |
| 10 | 十 | じゅう (juu) | とお (too) |
Why two readings for 4, 7, 9? し (4) sounds like 死 (death), く (9) sounds like 苦 (suffering). Japanese people avoid these readings in certain contexts. Use よん and きゅう as safe defaults.
Counting Higher: 11 to 99
Japanese numbers are logical. Just combine digits:
11 = 十一 (juu-ichi) = 10 + 1
20 = 二十 (ni-juu) = 2 × 10
25 = 二十五 (ni-juu-go) = 2 × 10 + 5
99 = 九十九 (kyuu-juu-kyuu) = 9 × 10 + 9
Big Numbers: 100 to 100,000,000
| Number | Kanji | Reading |
|---|---|---|
| 100 | 百 | ひゃく (hyaku) |
| 300 | 三百 | さんびゃく (sanbyaku) |
| 600 | 六百 | ろっぴゃく (roppyaku) |
| 800 | 八百 | はっぴゃく (happyaku) |
| 1,000 | 千 | せん (sen) |
| 3,000 | 三千 | さんぜん (sanzen) |
| 10,000 | 一万 | いちまん (ichiman) |
| 100,000,000 | 一億 | いちおく (ichioku) |
Key difference: Japanese groups large numbers by 10,000 (万), not 1,000 like English. So 100,000 is 十万 (10 × 10,000), not “100 thousands”. This trips up learners constantly.
The Number Kanji You Must Know
These kanji appear everywhere - prices, addresses, dates, ages:
一 二 三 四 五 六 七 八 九 十 百 千 万 億
Kanjijo’s N5 flashcard deck covers all number kanji with mnemonic stories and writing practice so they stick permanently.
Numbers + Counters
In Japanese, you can’t just say “three books.” You need a counter: 本を三冊 (hon o san-satsu). See our complete counters guide for the full system.
SRS flashcards, writing practice, and mnemonics for every number kanji. Free on iOS.