I pulled the plug in my bathtub and it drained in to my kitchen sink and overflowed onto my floor.The bathroom is upstairs.

Sheri, Clean your kitchen sink drain... No way around it...

Hi Mom,

I pulled the plug in my bathtub and it drained in to my kitchen sink
This doesn't sound like it's the sink drain. It sounds more like a blockage downstream from where the kitchen sink ties into the sewer main. (Do you get a back up when you flush as well?) If this were my call I would snake from the kitchen roof vent. Put out enough cable to reach the base and 20 feet more. Good luck, Tom

I agree with Tom, the sink drain appears to be open enough to let other parts of the home drain into it. The clog is obviously downstrean of the sink in a main drain line. I am surprised you did not get any water back into your toilet. The toilet sits lower and would get the back up first. This fact could be telling us a bit about the clogs location, up stream of toilet downstream of sink.

Ballenger1, he didn't get any water in the toilet, because the clog before the kitchen connects to toilet.

Milo. Maybe I said it wrong but "up stream of toilet downstream of sink.
" that's what I was trying to say. Yes, you are certainly correct but I think my explanation works.