Resizing for 500px upload

Leslie

Hi,
I am a member of 500 px and when I upload my shots they are fairly small in comparison to other people's. I believe this is a resizing issue. If I do not crop the shots at all, it seems they upload fine. If I do crop, as I do with my macros, then the sizing reduces. I am using the zoombrowser for sharpening, cropping, color. I'm very frustrated.
I am working with jpegs. Any thoughts?