40 in Japanese
Nearby Japanese Numbers
40 in Other Languages
About 40 in Japanese
The number 40 in Japanese is 四十 (yon-jū). The ordinal form — used for rankings, dates, and sequences — is 四十 (yoso/yosoji). The native counting form is 四十 (yoso/yosoji).
40 is an even number. In Japanese-speaking environments, 40 is the kind of number you'll hear and need to use regularly, from market prices to building floor numbers.
Learning 40 in Japanese is a step toward real communicative confidence. Numbers are unavoidable — they appear in every aspect of daily life, from prices and timetables to addresses and phone calls.
Learning Numbers in Japanese
What makes Japanese numbers challenging
Two parallel number systems (Sino-Japanese and native Japanese) that must be used in the right contexts. Counter words (classifiers) are mandatory — different objects require different counters based on shape, size, and category. The digits 4 and 7 each have two readings (shi/yon, shichi/nana) with strong cultural preferences: shi (4) sounds like death and is avoided. Large numbers are grouped by 10,000 (man) not 1,000, requiring mental re-grouping for English speakers. Sound changes (rendaku) alter some numbers when combined with counters.
Tips for learning Japanese numbers
Learn Sino-Japanese numbers first — they cover most situations including phone numbers, prices, dates, and math. Always use yon (not shi) for 4 and nana (not shichi) for 7 in everyday counting. Master the man (10,000) unit early for large numbers. Start with the general-purpose counter -tsu for objects before learning specific counters. Practice with Japanese prices (yen amounts are always large numbers since there are no decimal coins) for excellent real-world number comprehension.