Resizing image using GIMP

A lot of information is available on web about how to use GIMP and hence I would be very precise and brief in my description. Basically, I am interested in reducing the resolution of the image without changing its print size. For this, you need to remember this formula:

Print size = No. of Pixels / Resolution

So, for different resolution, we need to choose different of pixels so that the size remains same. The formula would be

NoP_1 / Res_1 = NoP_2 / Res_2

So, the new number of pixels for new resolution would be given by

NoP_2 = Res_2 * NoP_1 / Res_1


Load a new image onto GIMP from File -> Open menu and then go to view -> Info Window to know about current size and resolution. Now go to button Image -> Scale Image window and reduce the x and y resolution to a lower value and compute the x size and y size (in pixels) for this new resolution using above formula and change them accordingly. Then save the file in your desired format.