You said it!
Definition 1 of 1
Pro Tip 1/3Strong Agreement
Use it to express strong agreement or support for a statement someone has made. 
'The final exam is impossible without studying.' 'You said it!'
Pro Tip 2/3Emotional Emphasis
It carries an emotional weight, showing you feel the same way, not just agreeing logically. 
'I can't wait for the weekend.' 'You said it! This week's been tough.'
Pro Tip 3/3Informal
It's a casual expression, appropriate among friends but not in formal situations. 
'This place serves the best burgers.' 'You said it! They're unbeatable.'