Problems when exporting to WEB

[Silverchild]

Hello Gurus!

I'm trying to make a site and I editing the content in photoshop.
I make the layout with the width I need in pixels but when I export it to web it changes to bigger size and I have no clue why.

I change the canvas sizes and it's the right one but image size is bigger

It's been a while I don't use this option and I don't know if it's something new I don't know.
Can someone help me?

Thanks!

 

[inkpad.t]

did you use the slice tool to slice your images before you exported them ?