Divx Calculator Formula

I am looking some type of formula to calculate divx movies without, using an existing one thats on the net. Basically I want to be able to figure out the bitrate on paper to get a better answer, but I don't know the formula. Thanks if you get what I am trying to say and, can help.

you want to figure out the bitrate of the movie how? By the file size and length of video? Is that what you mean?

If that were teh case, you would first calculate the number of kilobits the file is. For that, you would take the file size (in megabytes), multiply that by 1024 to get kilobytes, then multiply that by 8 to get kilobits. Then divide that by the number of seconds the video is and you get the bitrate in kbps

({audio bitrate + video bitrate}/8) * length of movie (in seconds ) / 8. = size of file in bytes.

e.g. 600kb video, 160k audio, 190 second clip

size = ({(600+160)*1024}/8) * 190

= 18483200 bytes

= 18050 KB

= 17.62 MB

No I am trying to make the target size 700mb, 1,400mb, or 4,700mb. Basically I am trying to fit 3 movies on a dvd-r, and I am trying to get the closes size possible.