that's it

that's it

That's the end of that; I've had enough of that. That's it, everyone, thank you for listening. There are refreshments in the other room. That's it! I can't listen to you two fighting anymore, I'm getting out of here!

that's it

(spoken) also that's about it
everything necessary or related to a subject has been mentioned I read the comics in the Sunday paper – that's it. Well, I've told you all the news about us. That's about it.