How to get similarity score between 0 and 1 not relative score

[sushil sharma]

Hi,
 
We have a requirement where user would like to see a score (between 0 to 1) 
which can tell how close the input search string is with result string. So if 
input was very close but not exact matach, score could be .90 etc.
 
I do understand that we can get score from solr & divide by highest score but 
that will always show 1 even if we match was not exact. 
 
Regards,
Susheel