A 100 inch projector screen typically refers to the diagonal measurement of the screen, which is the distance from one corner to the opposite corner. To calculate the screen size in terms of width and height, you can use the Pythagorean theorem. Assuming the screen has a 16:9 aspect ratio (which is the most common for home theater screens), a 100 inch diagonal screen would be approximately 87 inches wide and 49 inches high. However, the exact dimensions may vary depending on the specific screen model and manufacturer.