one or two sizes (bigger, etc.); one or two levels (better, more mature, etc.)
Used to indicate a noticeable difference in size, degree, or maturity, often in comparisons. The phrase emphasizes a significant change, not just a slight one.
These shoes are one or two sizes too big.
He has matured a great deal.
Standard kanji-kana mixed spelling.
Variant with hiragana for the first part and kanji for 回り.
Variant with kanji for the first 回り and hiragana for the second.
Combination of 一回り (one size/level) and 二回り (two sizes/levels) with the particle も for emphasis.