Type a number, counter, date or time and get the correct reading in kana and romaji — including the irregular sound changes that trip everyone up (300 さんびゃく, 1本 いっぽん, 8日 ようか, 4時 よじ). The parts that change sound are highlighted. Everything runs in your browser.
| # | Kana | Romaji |
|---|
Japanese numbers look regular until you say them out loud. Two predictable sound changes reshape the readings whenever a number is combined with a place value (百, 千) or a counter (本, 匹, …):
The two often stack: 六百 = ろく geminates to ろっ and ひゃく shifts to ぴゃく → ろっぴゃく. In the readers above, every part that changed sound is highlighted so you can see exactly where and why.
| Base | + 百 (hundred) | + 千 (thousand) | + 本 (long objects) |
|---|---|---|---|
| 1 いち | ひゃく hyaku | せん sen | いっぽん ippon |
| 3 さん | さんびゃく sanbyaku | さんぜん sanzen | さんぼん sanbon |
| 6 ろく | ろっぴゃく roppyaku | ろくせん rokusen | ろっぽん roppon |
| 8 はち | はっぴゃく happyaku | はっせん hassen | はっぽん happon |
| 10 じゅう | — | — | じゅっぽん juppon |
A note on spelling: 10 in counters is shown here as じゅっ (juppon, juppun, jukkai…). The older reading じっ (jippon, jippun, jikkai) means exactly the same thing and is also correct — you will hear both.
Two regular sound changes are at work. Rendaku (連濁) voices the first consonant of the second part of a compound — so 三 (san) + 百 (hyaku) becomes さんびゃく sanbyaku, and 三 + 千 (sen) becomes さんぜん sanzen. Gemination (促音便) doubles a consonant after 1, 6, 8, 10 and 100 — so 一 (ichi) + 本 (hon) becomes いっぽん ippon, and 六 (roku) + 百 becomes ろっぴゃく roppyaku. These changes make the words easier to say, and they follow patterns you can learn. This tool applies them automatically so you always see the correct reading.
Japanese does not usually count things with bare numbers. Instead you attach a counter word that matches the shape or type of the thing: 本 (hon) for long thin objects, 枚 (mai) for flat thin objects, 匹 (hiki) for small animals, 人 (nin) for people, and so on. The number and counter often fuse and change sound — 一本 is いっぽん (ippon), not いちほん. Pick a counter above and this tool shows the reading for 1–10 plus any number you type, with the sound changes highlighted.
The first ten days of the month use special native-Japanese readings: 1日 is ついたち (tsuitachi), 2日 ふつか (futsuka), 8日 ようか (youka), 10日 とおか (tooka). A few later days are also irregular: 14日 じゅうよっか, 20日 はつか (hatsuka), and 24日 にじゅうよっか. From 11日 on (apart from those), days simply add 〜にち (nichi). Months are more regular, but watch 4月 しがつ, 7月 しちがつ and 9月 くがつ.
Both are correct. Historically じっぷん (jippun) was the prescribed reading, but じゅっぷん (juppun) is now by far the most common in everyday speech and is fully accepted. This tool shows じゅっぷん / juppun (and likewise じゅっかい, じゅっぽん, etc.); just remember that the じっ- forms mean exactly the same thing and you will hear both.