Large numbers in Japanese - Japanese Numbers

Japanese handles large numbers by grouping every four digits, not every three. The key units are 万（まん, 10,000）, 億（おく, 100,000,000）, and 兆（ちょう, 1,000,000,000,000）. Once you think in these blocks, you can read any long figure cleanly and quickly. This lesson gives you a clean place-value table, a step-by-step reading method, common sound changes, and dozens of worked examples so you can switch between western “commas every three” and the Japanese “units every four” without hesitation.

Rule of four: split the number from the right into groups of four digits. Attach 万 / 億 / 兆 to the left of each block in order, read each block like a normal 0–9999 number, and skip units whose block is zero.

Core large-number units

Unit	Reading	Power	Value	Usage notes
万	まん (man)	10⁴	10,000	Everyday large prices, population, salaries; foundation of grouping.
億	おく (oku)	10⁸	100,000,000	Company figures, real estate, city budgets, follower counts.
兆	ちょう (chō)	10¹²	1,000,000,000,000	National budgets, macroeconomics, market caps.
京	けい (kei)	10¹⁶	10,000,000,000,000,000	Rare outside science; included for completeness.

Within each block, you still use 千・百・十 (thousand, hundred, ten). For example, 一万二千三百四十五 reads as “1万 2千 3百 4十 5.” You never stack two large-unit kanji in a row: write the inner block with 千/百/十 and place the large unit after that block.

Place-value grid (group by four digits)

…兆	…億	…万	Units
[ 〇〜9999 ] 兆ブロック	[ 〇〜9999 ] 億ブロック	[ 〇〜9999 ] 万ブロック	[ 0000〜9999 ] 個の位

Example layout:

12 | 3456 | 0789 | 0123

= 12兆 3456億 789万 123

Zeros inside a block are read normally (e.g., 0700 → ななひゃく). If an entire block is 0000, skip that large unit completely—do not say “zero man.”

Step-by-step method

From the right, draw slashes every four digits: 9,876 / 5432 / 1000
Label blocks (right→left): Units, 万, 億, 兆.
Read each non-zero block as a normal 0–9999 number, then add the block’s unit.
Concatenate blocks with small, even pauses at the boundaries.

Worked example: 58,003,020,700

Blocks: 5 / 8003 / 0207 / 00 → actually 5 / 8003 / 0207 / 00 doesn’t line up; correct grouping is 5,800 / 3020 / 700 → 5800万 / 3020 / 700 is also off. Let’s do it cleanly:
Number: 58,003,020,700 → split 5 / 8003 / 0207 / 00 (兆 / 億 / 万 / Units). The Units block is 0700.
Reading: 五兆 八千三億 二百七万 七百
Romaji: go-chō hassen-san-oku nihyaku-nana-man nana-hyaku

Be methodical. On long figures, say the blocks out loud to yourself before the final read: “五｜八千三｜二百七｜七百”. That rhythm keeps you from losing digits.

Block readings 0–9999 (quick refresher)

Form	Reading	Notes
300	さんびゃく	/hyaku/ → /byaku/
600	ろっぴゃく	small っ
800	はっぴゃく	small っ
3000	さんぜん	/sen/ → /zen/
8000	はっせん	small っ
10–19	じゅう〜	じゅうよん, じゅうなな, じゅうきゅう

When a block equals 1, you still say “いち” before 千/百/十 inside the block (一千＝いっせん is common in formal writing but everyday speech prefers せん). For large units (万/億/兆), 一 is spoken: 一万＝いちまん, 一億＝いちおく, 一兆＝いっちょう（*促音化）.

Many examples with answers

Everyday finance & headlines

75,000 → 七万五千（ななまんごせん）
1,280,000 → 百二十八万（ひゃくにじゅうはちまん）
35,800,000 → 三千五百八十万（さんぜんごひゃくはちじゅうまん）
120,000,000 → 十二億（じゅうにおく）
2,450,000,000 → 二十四億五千万（にじゅうよんおくごせんまん）

Tech & population

98,765,432 → 九千八百七十六万五千四百三十二
500,000,000 → 五億（ごおく）
1,234,000,000,000 → 一兆二千三百四十億
20,030,000,000 → 二百億三千万
7,000,010,000 → 七十億一万

Templates you can reuse

◯◯万（えん）台 — in the ◯◯-ten-thousand range: 二十万円台 (somewhere in the 200k yen range).
約◯◯万／億 — about ◯◯ man/oku: 約五億.
◯◯兆円規模 — a ◯◯-trillion-yen scale: 数兆円規模の投資.

Don’t insert western commas when writing kanji numerals. Either write fully in kanji with units (三千四百五十六万七千八百九十) or in Arabic digits with Japanese units (3456万7890) or simply commas (34,567,890)—but don’t mix styles mid-number.

Practice set (read out loud)

Read each number using 万・億・兆. Answers follow immediately so you can self-check.

Number	Blocks	Answer (kanji)	Romaji sketch
8,640,000	864｜0｜000	八百六十四万	happyaku-roku-jū-yon-man
304,050,600	30｜4050｜600	三十億四千五十万六百	san-jū-oku yon-sen go-jū-man roppyaku
12,000,000,000	120｜0｜0000	百二十億	hyaku-ni-jū-oku
1,000,300,070,000	100｜03｜0070｜0000	百兆三億七千万	hyak-chō san-oku nana-sen-man
47,005,001	4｜7005｜0001	四億七千五万一	yon-oku nana-sen go-man ichi

Converting from western commas to Japanese units (mental workflow)

Hide the commas and re-group four digits from the right.
Assign units from right to left: Units → 万 → 億 → 兆.
Say each block as a normal number; attach the unit.
Compress obvious 1’s if the context allows (いちせん→せん), but keep いち for large units (いちまん, いちおく, いっちょう).
Keep a steady beat; don’t accelerate at the end.

With a few minutes of daily drills you will find that 万 / 億 / 兆 stop feeling exotic and become the fastest way to think about big numbers.

Large numbers in Japanese, man, oku, cho, with a clean place value table