Question: is m the same as mb in photoshop?
Answer: One megabyte is equal to 1024 kilobytes. So to find the total image size in megabytes, divide the number of kilobytes (43,139.94) by 1024, which gives us 42.1 megabytes (or MB, although for whatever reason, the Image Size dialog box shortens "MB" to just "M"). Photoshop agrees with our calculations.