倍|ばいbai[0]heiban (flat)

1. no-adjectivedouble; twice (as much)
   彼かれは私の倍ばい食たべた。↗

   He ate twice as much as I did.
2. countertimes (as much); -fold
   あの山やまはこの山やまの５倍ばいの高たかさである。↗

   That mountain is five times as high as this one.
3. counter1-nth; 1 to n; 1 in ne.g. 40倍 = 1 in 40

• Synonym二倍にばいNeutralNeutral word for exactly twice, as in 「二倍の量」; more explicit than 「倍」.
• Related倍増ばいぞうWrittenWritten word for growing to about twice the size, as in 「売上倍増」; it stresses the result of the increase rather than the ratio itself.
• Related倍加ばいかFormalFormal word for doubling or multiplying, as in 「負担が倍加する」; more formal in tone than 「倍」.
• Related倍するばいするWrittenWritten word for being twice as much as something, usually in the pattern 「〜に倍する」.
• Antonym半分はんぶんNeutralNeutral antonym of 「倍」: to cut something to half, as in 「量を半分にする」.

Use 「倍」 for times and multiples in general, and 「二倍」 when you mean exactly twice. For growth to double, 「倍増」 stresses the result; 「倍加」 is formal; 「倍する」 is written, as 「〜に倍する」. To halve, say 「半分」.

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

1. （バイ）二に倍ばいの意い。
2. （バイ）ある量りょうを基準きじゅんとなる数量すうりょうで割わった値あたいに付ふして、基準きじゅんとなる量りょうに対たいする比率ひりつを示しめす助数詞じょすうし。ある数かずを同おなじ分量ぶんりょうに増ふやすこと。他動詞たどうしとしても用もちいる。