lol yeah. The tape measure is the way to go! .. Oh just go to some big computer store/warehouse and pinpoint a monitor that "looks" something like urs. 2" is a big difference - so it's easy.
If you do use a ruler, just make sure you measure from the diagonal. That's the only way you will get a good measurement of what size monitor you have...
Measure the screen from corner to corner,Most of the time it is an inch smaller than what it's supposed to be,For example a normal crt 17inch monitor should have a veiwable screen size of 16inch or a bit more.
Yeah but remember that 17 inches is referring to the actual size of the cathode ray tube. The edges of it are concealed behind the plastic case of the monitor, so you actually see less than this.