The answer to this question depends on two values, your screen size and the throw ratio of your projector. The throw ratio of your projector is usually shown as a range. This is the ability of the zoom lens of your projector to increase or decrease the size of the image. Most ceiling projectors come with a lens that has a zoom option on it. Hence why the throw ratio is almost always a range. You have to enter both these numbers into the yellow cells in spreadsheet as shown below.
Before using the spread sheet please read the following carefully: i. Make sure you are in the correct aspect ratio. If you are planning to put in a 16 by 9 screen, make sure you are in the 16 by 9 sheet. ii. This spreadsheet is for guide only, we do not guarantee the accuracy of this sheet and take no responsibility for damages resulting form its use. It should be strictly used as a guide. The ultimate "go to" document is your projector's user manual.
Before you download this spreadsheet, you agree that you will not hold us responsible for any damages resulting from any errors in the spread sheet. Click here to download the spread sheet.
In order to get a good estimate of your projector's distance from the screen, you will need to enter the throw ratio of your projector into this spreadsheet. This consists of a range, i.e. two numbers a smaller number and a larger number. You will need to enter both these numbers as shown in the image below.
Please note that no all projectors can do all sizes of screens in a certain room. You may come across situations where your projector throw ration for a certain size of screen requires the projector to be further away than the entire lenght of the room. We therefore strongly recommend that you always go to the experts when it comes to doing home theatre.
Having said all that, we believe that this spread sheet is quite accurate in giving you a fair idea if a certain projector will work with a certain screen size within the confines of your theatre room.
The spreadsheet has got most of the common screen size already entered into it. However, if you are buying a screen in a very unusual size, please enter the size of your screen in the yellow custom size cells. The spread sheet will show you the distance of your projector from your screen.
This sheet goes one step further and works out the area of your screen. When fed with the lumen output of your projector (in the yellow cell ANSI lumens),it can work out if you have enough lumens in your projector to make your screen bright enough to meet certain industry standards.