be down to (something)

be down to (something)

1. To be or be considered the essential or most important factor or thing. Our success is down to our persistence and precise planning.
2. To have something reduced to a minimal amount. I can't come with you tonight. I'm down to my last dollar, I'm afraid. We're down to the last two days of the competition, so be sure to enter for your chance to win!
See also: down