Hello NDao. To give you the best recommendation, we would need to confirm the exact distance between the projector's location and the screen. For reference, if the projector is placed approximately 30 feet away, we recommend using a 200-inch screen. For a screen size of 72 or 100 inches, we recommend placing the projector about 11 - 13 feet away from the display. Regards, Kevin - The Epson Team.