How to say "dozens" in Japanese

• 数十すうじゅうCommon
  no-adjectiveThe plain estimating sense of 'dozens': an indefinite number somewhere in the tens, as when guessing how many people, times, or things. It also covers 'decades', that is, several tens of years.
  その恐おそろしい事故じこで数十すうじゅう人にんが負傷ふしょうした。↗

  Dozens of people were injured in the terrible accident.
• 何十なんじゅうCommon
  nounAlso 'dozens' or 'scores', but with the sense that the number is unknown or strikingly large — dozens upon dozens. Suits statements where the speaker is impressed or has lost count, rather than a calm estimate.
  彼かれは何十なんじゅう冊さつも英語えいごの本ほんを持もっている。↗

  He has dozens of English books.

Choose 数十 for a neutral estimate of several tens, including decades of years; choose 何十 when the number of tens is unknown or strikingly large, as in 'dozens upon dozens'.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 数十すうじゅうdozens
• 何十なんじゅう(several) tens