Hi. i have been shown a way in photoshop to tell me what best pixel resolution i should do architectural renders at, for any size paper, for a desired DPI. it seems very efficient by changing each of the parameters. turning resampling on will change the output too.

it was done in PS by first creating a canvas and then using image setting/size to get the right dialog box with the parameters.

I cant find how to do this in Gimp, because when i change the DPI in image setting/size it doesnt change the pixel sizes automatically!

There must be a simple way to do this like PS has. obviously i am a noob

Thanks