Add Measurement feature to range slider - wordpress

Hello, I have a modified version of contact form 7 plugin for wordpress. It has been modified to display the output of the range slider function underneath. It works perfectly. However I would like to add a function: I would like to be able to have the output be in feet and inches ex. 7' 11" (automatic). It would automatically move one inch at a time, so the interval option would not be necessary. I would still like the min and max value options, which would be how many feet. (there are twelve inches in a foot) I would like to be able to choose which range sliders this applies to...perhaps using the class feature built into contact form 7, as not all range sliders in my form will be using feet and inches. Please read the description and ask any questions in you're not clear on anything. Thanks.