What's a good FLAC/Lame file size ratio?

[trains are bad]

I say I have 100GB of music in flac. How much space would that take up in good Lame mp3s?

All I need is a swag, but I wonder how precisely the two could be correlated; if one could write a program to calculate it.

 

[krmathis]

If we say that your FLAC files average at 800Kbps, and you encode with LAME -V2 (~192Kbps). Then 25GB should not be far off.