Totally noob, wanted to crop as photoshop but can´t

[CaLy]

My question is: is there a way to crop an image, like in photoshop, where you put the crop size you want, and it crops to that selection?


Source image: http://i.imgur.com/NT7yMLA.jpg  

Photoshop crop: http://imgur.com/BwCLKOS  

Gimp crop: http://imgur.com/c5HYTDh


Why the crop size isnt the same in photoshop and in gimp? And also, is it me or the quality is better in PS than gimp?  I am doing all wrong, right? Thank you for reading this n00b question.

 And have a nice friday, and better weekend in advance!  


Carlos Octavio