Well, I would use the formula
((input - min) * 100) / (max - min)
For your example it would be
((65 - 46) * 100) / (195 - 46) = 12.75
Or a little bit longer
range = max - min
correctedStartValue = input - min
percentage = (correctedStartValue * 100) / range
If you already have the percentage and you're looking for the "input value" in a given range, then you can use the adjusted formula provided by Dustin in the comments:
valvalue = ((percentpercentage * (max - min) / 100) + min