0.08333 inches. A similar lens with similar focal length on both 1/3" and 1/4" CCD will give a more narrow FOV on the 1/4".
Thanks Rogier for your reply one extra question how can i calculate field of ciew by know camera lens i mean if camera lens 50mm or 12mm how can i know how far camera show
Mohammed, try this lens calculator - it's a very simple one: select your imager size and lens focal length, and it will tell you the FOV angle.
Or try this slightly more inclusive one where you can enter your imager size, distance to target, and width of the area to be covered, and it will provide the lens needed.
one more Thing Matt how can i know the perfect height for camera
I read this article before but i was ask if there calculator can help me for that
There is at least one online calculator that includes height calculations: This one by JVSG, who also make a design application for Windows that will help with more complex designs: IP Video System Design Tool
However, as John's link shows, the "perfect" height will depend on a lot of factors, including the view you need. Put it too low, you may not cover as much area; put it too high, you'll only be looking at the tops of things. A program that can give you simulated views, like the one above, will help... experience will help as well. Sometimes you need to just get up on a ladder or lift, and see for yourself what the picture will look like from various heights.
Since we are being precise it is exactly 2mm or 0.0787401575 inches as discussed here.:)