How to say "factor" in Japanese

• 要素ようそJLPT N3approx.Common
  nounThe general-purpose word for a factor as one of the elements making up a situation or result; it equally covers 'component' and 'item'. This is usually the safest choice for the abstract sense.
  教育きょういくは重大じゅうだいな要素ようそである。↗

  Education is a critical element.
• ファクターCommon
  nounThe loanword for 'factor'; it covers the same abstract sense as 要素 and the two are often interchangeable, with ファクター feeling natural where the English word itself would be used.
• 因子いんしCommon
  nounThe word for 'factor' in scientific, mathematical, and medical writing — a measurable or causal factor in a technical analysis. For the everyday abstract sense, 要素 is more natural.
  私の理解りかいではその二ふたつの実験じっけんには共通きょうつうの因子いんしはない。↗

  In my understanding, those two experiments do not have common factors.
• 因いんCommon
  nounEssentially means 'cause'; as a standalone word for 'factor' it is rare, and this is seldom the word you want — reach for 要素 or 因子 instead.
• 係数けいすうCommon
  nounThe mathematical term for 'coefficient'; its 'factor' sense is numerical, a number by which a quantity is multiplied. It is not used for the abstract 'contributing element' sense of factor.

For the everyday abstract sense use 要素 or the loanword 「ファクター」; use 因子 for scientific, mathematical, and medical factors; 因 essentially means 'cause' and is rarely the right choice; 係数 is only for numerical coefficients.

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

• 要素ようそcomponent
• ファクターfactor
• 因子いんしfactor
• 因いんcause
• 因数いんすうfactor
• 約数やくすうdivisor
• 係数けいすうcoefficient
• 材料ざいりょう(market) factor