An order of magnitude difference; far out of proportion — used to say something is in a completely different league compared to something else.
彼の実力はチームメイトと桁違いだ。
His ability is in a different league from his teammates'.
予算が桁違いに多かったので、計画は大幅に変更された。
Because the budget was an order of magnitude larger, the plan was greatly changed.
その企業の売上は業界内で桁違いだ。
That company's sales are incomparable within the industry.