漢数字

Kanji Numbers

Japanese uses both kanji (一, 二, 三) and arabic (1, 2, 3) numerals. This guide covers how to read number kanji and when to use them.

Basic Digits 一 through 十

ValueKanjiHiraganaRomaji
0れいrei
1いちichi
2ni
3さんsan
4よん / しyon / shi
5go
6ろくroku
7なな / しちnana / shichi
8はちhachi
9きゅう / くkyuu / ku
10じゅうjuu

Larger Numbers 百, 千, 万, 億, 兆

ValueKanjiHiraganaRomaji
100ひゃくhyaku
1,000せんsen
10,000まんman
100,000,000おくoku
1,000,000,000,000ちょうchou

When to Use Kanji vs Arabic Numerals

Vertical writing kanji
三月十五日

Books, newspapers, and traditional documents use kanji in vertical text.

Horizontal writing arabic
3月15日

Modern horizontal text typically uses arabic numerals.

Legal/financial docs kanji
金壱萬円

Formal kanji (大字, daiji) prevent alteration — 一 could become 二 or 三, but 壱 cannot.

Prices and amounts arabic
¥1,000

Everyday prices use arabic numerals for clarity.

Addresses either
三丁目 or 3丁目

Both forms are common. Official documents tend toward kanji.

Ages either
二十歳 or 20歳

Kanji is traditional (especially 二十歳, hatachi), arabic is modern.

Dates either
一月 or 1月

Kanji in formal/vertical, arabic in casual/horizontal writing.

Counters either
三人 or 3人

Small numbers often use kanji; larger numbers use arabic.

Formal Kanji 大字 Daiji

Formal kanji exist to prevent fraud on financial documents. Simple strokes like 一 can be altered to 二 or 三, but formal kanji like 壱 cannot be easily modified.

StandardFormalValue
1
2
3
5
10
100
1,000
10,000
Example
金壱萬円 On a check: ¥10,000

Cultural Notes

4 Unlucky

The reading し (shi) sounds like 死 (death). Avoided in hospitals (no room 4), gifts, and floor numbers. よん (yon) is preferred in most contexts.

9 Unlucky

The reading く (ku) sounds like 苦 (suffering). Similarly avoided in hospitals and formal contexts. きゅう (kyuu) is the safer reading.

8 Lucky

Considered lucky because the kanji 八 widens at the bottom, suggesting expanding prosperity (末広がり, suehirogari).

7 Lucky

Lucky number in Japan, associated with the Seven Gods of Fortune (七福神, shichifukujin) and the Tanabata festival on July 7th.