expression
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.
この靴は一回りも二回りも大きい。
These shoes are one or two sizes too big.
彼は一回りも二回りも成長した。
He has matured a great deal.
Means 'one size' or 'one level', while 一回りも二回りも emphasizes a larger, more significant difference.
Combination of 一回り (one size/level) and 二回り (two sizes/levels) with the particle も for emphasis.