What is the meaning of 「オレより頭ひとつぶん低い...」？


Original sentence was 「オレより頭ひとつぶん低いAを立たせてやったのはいいけど...。」 where A would be
someone's name.

I feel like it would mean that A is shorter than the speaker or just "lower to
the ground" since they both fell recently, but then the いいけど seems strange.
This is the first time I've ever come across the phrase ひとつぶん which I feel
would mean "one part/portion" on it's own, but doesn't fit with 頭ひとつぶん低い.

I want to translate it as the speaker helping A (who is lower than the
speaker?) stand up again after falling, but is the いいけど them hesitating
instead of going through with it?

Edit: rather than hesitating, I think the いいけど is out of shock since the next
sentence goes on to talk about how thin A really is which they only notice
after helping them up.




It is translated as "A is a head shorter than B. ～ひとつぶんの～ means "a unit of
measurement". You may change ひとつ to other numbers. For example, 頭一つ分の高さ(the
height of one head), 東京ドーム3つ分の面積(the area of three Tokyo Dome).

