How to resize an SVG image in Illustrator to PNG with 1200 pixels width?

I want to convert an SVG image to a PNG image that is 1200 pixels wide (as recommended by a journal). To do this, I changed the units to pixels in Illustrator and scaled the image to a W value of 1200. However, when I check the dimensions in the file properties after exporting, it says 2258 x 810 pixels. Can anyone tell me why this is and how I can scale the image correctly?