“It's all yours.”
You were in a restaurant bathroom, and someone knocked on the door to get in. Now you've finished and you're leaving the bathroom. You say this to the person waiting outside.
It's all yours.
You say "It's all yours" when you're finished using something and want to tell the next person that they can use it:
A: Hey, are you done with that?
B: Sure, it's all yours.
You can also use this phrase when you're almost finished using something. For example, if someone in your family wants to use your computer, you can say:
Let me just do a few more things, and then it's all yours.
"It's all yours" is friendly and casual.