How to say "population" in Japanese

• 人口じんこうJLPT N4approx.Common
  nounFor 'population' meaning the number of people who live in a country, city, or area — the figure given in censuses and demographic reports — this is the word to use.
  紀元きげん２０２０年ねんまでには、この市しの人口じんこうは倍増ばいぞうしているだろう。↗

  By the year 2020, the population of our city will have doubled.
• 住民じゅうみんJLPT N3approx.Common
  nounPrimarily 'inhabitant' or 'resident': the people living in a place. As 'population' it keeps that human, collective nuance — use it when you mean the residents themselves, not a headcount or statistic.
  ウェストハンプトン州しゅう住民じゅうみんによって、議会ぎかいの構成員こうせいいんとして選出せんしゅつされるのです。↗

  We're chosen by the people of Westhamptonshire County to be members of the council.

Choose 人口 for 'population' as a number or statistic; 住民 means the residents of a place, so it fits 'population' only when you mean those people collectively rather than a count.

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

• 人口じんこうpopulation
• 住民じゅうみんinhabitant
• 戸口ここうhouses and inhabitants
• 口数こうすうpopulation
• ポピュレーションpopulation
• 母集団ぼしゅうだんpopulation
• 個体群こたいぐんpopulation (e.g. of animals)
• 個体数こたいすうpopulation (of animals, etc.)
• 実装密度じっそうみつどpopulation (density)
• 人頭じんとうnumber of people