Hi kirk,
I think there's a bit of confusion with what I mean.. I'm not talking about the actual file size, but the amount of memory the image takes up... If you load a jpg file into photoshop for example, and it's only 3 or 4mb of disk space, you'll see photoshop might report it as a 20 or 30mb image.
Using a calculator would not be useful, because the best time to resize the image before uploading or emailing is after the crop has been applied, so that's a variable to consider.
I'll pm you the photoshop script when I get back from this shoot and you can see what I mean. The resulting file sizes are usually between 500k and 1.2mb compressed, but the image size is always bang on 7mb uncompressed, and guaranteed not to explode the newspaper's library. It also doesn't matter what the width and height are, the script always resides in proportion.
I have a similar plugin for lightroom which will resize to the total number of pixels, which is effectively the same, but you have to work out the bit depth and mb yourself... Which to get a standard 7mb uncompressed) 8bit rgb file is (from memory so I'll have to double check), 1024x1024x7x3
I'll post script later
J