Large Number Unit Converter (Japanese–English)
Enter a number to see it expressed in both Japanese units (万, 億, 兆) and English units (million, billion, trillion). Includes a quick-reference table and real-world scale examples to clear up the "1億 = 1 million?" confusion.
Complete Japanese–English Unit Reference
Every named unit from 100 (one) to 10100 (googol), side by side.
| Exponent | Japanese | English |
|---|---|---|
| 100 | 一 （いち） | one |
| 101 | 十 （じゅう） | ten |
| 102 | 百 （ひゃく） | hundred |
| 103 | 千 （せん） | thousand |
| 104 | 万 （まん） | — |
| 106 | — | million |
| 108 | 億 （おく） | — |
| 109 | — | billion |
| 1012 | 兆 （ちょう） | trillion |
| 1015 | — | quadrillion |
| 1016 | 京 （けい） | — |
| 1018 | — | quintillion |
| 1020 | 垓 （がい） | — |
| 1021 | — | sextillion |
| 1024 | 秭 （じょ） | septillion |
| 1027 | — | octillion |
| 1028 | 穰 （じょう） | — |
| 1030 | — | nonillion |
| 1032 | 溝 （こう） | — |
| 1033 | — | decillion |
| 1036 | 澗 （かん） | undecillion |
| 1039 | — | duodecillion |
| 1040 | 正 （せい） | — |
| 1042 | — | tredecillion |
| 1044 | 載 （さい） | — |
| 1045 | — | quattuordecillion |
| 1048 | 極 （ごく） | quindecillion |
| 1051 | — | sexdecillion |
| 1052 | 恒河沙 （こうがしゃ） | — |
| 1054 | — | septendecillion |
| 1056 | 阿僧祇 （あそうぎ） | — |
| 1057 | — | octodecillion |
| 1060 | 那由他 （なゆた） | novemdecillion |
| 1063 | — | vigintillion |
| 1064 | 不可思議 （ふかしぎ） | — |
| 1068 | 無量大数 （むりょうたいすう） | — |
| 10100 | — | googol |
🟢 Green rows mark where Japanese and English share a name for the same exponent (e.g. 1012: 兆 = trillion). 🟡 The amber row 10100 is googol — the number that inspired the name "Google".
Conversion tips
- When you see "億" (10^8), the English is hundred million. "1億円 = 1 million yen" is a common mistake — the correct translation is 100 million yen.
- "10億" = 1 billion. When you hear "a billion dollars" in English news, think of it as 10億ドル in Japanese.
- "1兆" = 1 trillion (= 10^12). This unit lines up in both languages. Japan's national budget is about 110兆円; the US GDP is roughly 25 trillion dollars.
- "100万" = 1 million (= 10^6). "Million" only appears at the 1,000,000 mark.
FAQ
Side Note — Why the 4-digit vs 3-digit gap exists
The Japanese large-number system, inherited from ancient China, uses a myriad-based (万進法) system — units change every four digits: 万, 億, 兆, 京… Standard English uses a thousand-based system — thousand, million, billion… As a result, 10,000 (1万) has no single English word and must be written as "ten thousand."
The confusion is especially common in business and media. "How much is 10億円?" — since 10億 = 10^9 = 1 billion, the answer is "1 billion yen." A frequent error is translating 1億円 as "1 million yen," when the correct expression is "100 million yen." Use this converter to get it right every time.