You're telling me! INFORMAL
used to say that you strongly agree with what someone has just said:
"Stephen's in such a bad mood today." "You're telling me!"

[TahlilGaran] Advanced Learner's Dictionary ▲

You're telling me!
[informal]
something that you say to emphasize that you agree with something someone has just complained about because you have experienced it yourself.
'Brenda's really bad-tempered these days.' 'You're telling me!'

[TahlilGaran] English Idioms Dictionary ▲

You're telling me!
used to show that a thing is so clear that it doesn't need to be said
"This restaurant is very expensive and the food is not so good."

"You're telling me."

[TahlilGaran] English Idioms Dictionary ▲

you're telling me
interj., informal
■ Used to show that a thing is so clear that it need not be said, or just to show strong agreement.
"You're late." "You're telling me!"
Compare: YOU BET, YOU SAID IT.

[TahlilGaran] English Idioms Dictionary ▲