Problem calculating VBR Bitrate in a xVCD

[Animotion]

Hello, i'm new here and i have a question:

Anyone know how can i calculate an exacltly bitrate for a VBR in a xVCD ????

I want to make a divx picture in widescreen (640 x 360) in a full cd, the movie lenght is: 1hr 14min and 13 seconds, and i want to make in variable bitrate, but i need to compress the picture several times to have the exactly size to keep in a full cd, i want to know if anyone have a better method to calculate this tipe of bitrate.

Thanks

[holistic]

https://www.videohelp.com/calc.htm

..1hr 14min and 13 seconds.

For a 700Mb CD with audio@128 then video is ~1170


Edit : afterthought ---- I forgot about "overburn" and ignoring the error corection. If that case a bitrate of over 1300 if your burner will got to ~780Mb+.