Why are my pictures coming out small when i upload them? - 1

So i have a nikon d3100 and when i upload my pictures to my macbook they come out normal in iPhoto but when i upload them to facebook or tumblr they come out small. I already checked the settings on my camera and the pictures are set for large… So i don't really get what's going on.

What resolution do you have your camera set?

It should be Large and Fine JPEG

FaceBook automatically reduces the file size when you upload to their sites. Tumblr may do the same