projector placement / distance relative to screen size

[theballboy]

Hi all,
wondering if anyone can signpost me to working out the distance my projector should be from my screen for correct image size
(Havnt purchased projector or screen or launch monitor yet as still planning)
From my research it seems its going to be a 4:3 ratio.

However I'm pretty sure the screen size will be around 2.45m(8ft) to 2.7m (8.75ft) wide x 2.45m (8ft) high
I have around 12ft length to work with after leaving 1ft behind for placement of mats and projector - (total room lengh is 20ft but want to leave space for seating etc behind me

Would really appreciate advice so as to not make a noobie mistake

Thanks

[Bubba22]

You need to figure out where you want the projector and then use the throw distance calculator from Projector central, to get which one will fit your needs.

https://www.projectorcentral.com/projection-calculator-pro.cfm

[theballboy]

Ah i see, so I can choose a distance that suits (ie 10m) then enter the diagonal of screen and it will tell me which projectors are suitable?
Or I can find a projector first and put that in and it'll advise position based on screen size?