be dollars to doughnuts that

be dollars to doughnuts that (something happens)

To be assured or certain to happen. The idea is that one is so confident in a particular outcome that they would bet money against something less valuable. It's dollars to donuts that Kevin will be late tonight—he's never on time.
See also: dollar, doughnut, that
Farlex Dictionary of Idioms.

be dollars to doughnuts that

be a certainty that. North American informal
1936 James Curtis The Gilt Kid If he were seen it was dollars to doughnuts that he would be arrested.
See also: dollar, doughnut, that
Farlex Partner Idioms Dictionary
See also:
  • be dollars to doughnuts that (something happens)
  • dollars to doughnuts, it's
  • donut
  • bet on it
  • bet on
  • bet on (someone or something)
  • you bet your bottom
  • bet (one's) life
  • you can bet your bottom dollar (on something)
  • bet (one's) boots