# Japanese Numbers

> Learn Japanese number readings, from wa-go and kan-go to counters for everyday objects.

Canonical: https://inkujapanese.com/japanese/numbers
Last updated: 2026-04-21

How to count from 1 to a billion in Japanese. The two reading systems, the counters, and the big four irregularities.

[Bao H.](https://inkujapanese.com/authors/bao-hua)Updated April 21, 20268 min read

## Short answer

Japanese has two number systems (the native wa-go for 1-10, the Sino-Japanese kan-go for everything) plus counters that change the reading depending on what you're counting. The full system fits in a single study session.

Number systems

2 (native + Sino-Japanese)

Counters in active use

~350, but 10 cover daily life

Safe fallback counter

-tsu (hitotsu, futatsu...)

Critical irregulars

4, 7, 9 each have two readings

## The two systems

Wa-go (native Japanese): hitotsu, futatsu, mittsu, yottsu, itsutsu, etc. Used for objects up to 10. Falls out of use beyond that.

Kan-go (Sino-Japanese): ichi, ni, san, shi, go, roku, shichi, hachi, kyū, jū. This is the system used for everything else. Counts up cleanly into the millions and billions.

Both systems coexist for 1-10. You'll hear both in real Japanese: hitotsu (one thing) vs ichi (the number 1). Beyond 10, kan-go takes over completely.

## The four irregular readings

4 has two readings: yon (native) and shi (Sino-Japanese, also the word for death, usually avoided). Yon is the safer default.

7 has two readings: nana (native) and shichi. Nana is the safer default in counting.

9 has two readings: kyū (default) and ku (used in 9 o'clock and September, 九月 kugatsu). Kyū is the safer default.

0 is rei (formal) or zero (English loan). Both are common.

## Counters

Japanese requires counter words attached to numbers depending on what you're counting. People use -nin (一人 hitori, 二人 futari, 三人 sannin). Long thin objects use -hon (鉛筆一本 enpitsu ippon, one pencil). Flat objects use -mai. Small animals use -hiki. Large animals use -tō.

Start with common counters for people, days, months, hours, minutes, ages, floors and general things. The generic counter -tsu (hitotsu, futatsu) can be used for some objects.

## Related reading

- [Grammar overview](https://inkujapanese.com/japanese/grammar)

- [N5 vocabulary list](https://inkujapanese.com/guides/jlpt-n5-vocabulary)

## Common questions

### How do I say my age in Japanese?

Use the -sai (歳) counter: 25-sai is twenty-five years old. The exception is 20, which is hatachi (二十歳). Hatachi is a fixed reading you have to memorize.

### How do I count days vs days-of-the-month?

Day-of-the-month: tsuitachi (1st), futsuka (2nd), mikka (3rd)... up to 10, then jūichi-nichi (11th), jūni-nichi (12th)... Numbers of days: ichinichi (1 day, irregular), futsuka (2 days), mikka (3 days)... Same readings, different meaning by context.

### Are Japanese numbers used in math?

Mostly Sino-Japanese (ichi, ni, san) for arithmetic. Native readings (hitotsu, futatsu) appear in counting objects but not in equations. Computer programming and academic math use Sino-Japanese.