A medium-sized monitor is usually the same size. The standard medium size is 24 inches, which is 61 centimeters. That's suitable for most usage situations, but 23 and 25 inches are also part of the medium range. Because you sit closer to a monitor than to a television, 23 to 25 inches is a good size for everyday use, photo editing, and watching movies. If you prefer more screen space for gaming or professional photo editing, for example, choose a 27-inch monitor or bigger.