bitrate calculation nightmare

[jii]

i want to use tmpge to encode svcd. when i get to the section in the wizard where im suppose to put in the type of cd (80min) and the percentage of disk space(100%) ...i get a very low bitrate 570. im only trying to encode 67min of video and when i use the vcdhelp bitrate calculater ...for those specifications the bitrate the comes out is 1391... of course when i put 1391 in the tmpge it tells me that its not going to fit on one cd (it comes out to 203% - which is basically 2 CDs for 67min)
please help....
here is some more info:the source file is divx inwhich the 67min have a file size of 750mb (this is usally twice the usual size for a movie in divx but for some reason it was encoded as such- i dont think this fact should change the output but i thought ill just through it in here in case it does)
thanks guys

[Douglesh]

Well then dont use wizard/ According to FitCD your bitrate should be around the 1400-1450 mark, so use that