An image magnification ratio indicating device of the invention includes a processor having hardware, and the processor is configured to: magnify, or not, an image at a predetermined magnification ratio and transmit the image; switch an image transmission destination; instruct change of an image as a transmission target, and change a first magnification ratio to a second magnification ratio according to the change of the image as the transmission target or the switching of the image transmission destination and indicate the magnification ratio.