all for naught

(all) for naught

In vain; for nothing. Said of an effort that has resulted in failure. All of my hard work on that budget report was for naught when the computer system crashed.
See also: naught
Farlex Dictionary of Idioms.

all for naught

Everything done has been in vain. Today a poetic word for “nothing,” naught formerly meant “morally bad” or “worthless.” Thus the King James version of the first Book of Kings (2:19) says, “The water is naught and the ground barren.”
See also: all, naught
The Dictionary of Clichés by Christine Ammer
See also:
  • (all) for naught
  • naught
  • go for nothing
  • come to naught
  • failure
  • abysmal failure
  • a waste of energy
  • energy
  • a good deed is never lost
  • cut one’s losses