at a guess

at a guess

As an estimate or speculation. At a guess, I think we're going to need about 10 more chairs.
See also: guess
Farlex Dictionary of Idioms.

at a ˈguess

as a rough estimate: At a guess, I would say there were about thirty people in the room.
See also: guess
Farlex Partner Idioms Dictionary
See also:
  • a stab in the dark
  • I guess not
  • take a guess
  • make a guess
  • what do I know
  • What does (one) know?
  • guess at
  • guess at (something)