The number of lumens needed largely depends on the size of your screen. Of course, the smaller the screen, the lesser amount of lumens needed. For 60 to 80 inches, try 1000 – 2000 lumens. If you have a screen size of 80 – 120 inches, you would normally need around 2500 – 3500 lumens. If you have a screen size larger than 120 inches, I would suggest using over 3500 lumens.