beamers: screen size and throw distance
When you want to know what size the beamer will project with the distance you have available, look at the schedules:
HD-prepared:
Panasonic PT-AX 200E: screen size and throw distance
full HD
Panasonic PT-AE 4000E: screen size and throw distance
Epson EH-TW3200: screen size and throw distance
Epson EH-TW5300: screen size and throw distance
Epson EH-TW6700: screen size and throw distance
InFocus IN3118HD: screen size and throw distance
JVC LX-FH50: screen size and throw distance
Optoma GT1080e: screen size and throw distance