juice instead of fruit

[noobsauce]

Did a search and cant seem to find an answer. I know it is possible to use a store bought juice but im not sure how much a person would use compared to the actual fruit. What i was thinking of specifically was a slivovitz. A friend loves the stuff and it is something i would like to try a small amount of. Plums dont seem to be very common around at the stores atm so was thinking of using prune juice (it is plums right??.lol) Now i dont really have an idea what amounts to use...For example for 1 gallon i should use how much juice to how much sugar (yeah not authentic but i hope it will be close) and are nutrients required? Just would like a couple pointers if possible.

[tater]

http://www.nutritiondata.com/facts/frui ... ces/2040/2

[noobsauce]

Looked at that before Tater but ty. In fact the bottle of juice has the sugar content right on it. I should have explained myself better. I was more wondering about taste-wise and such type info. Sorta like "1 quart of plum juice is sorta = to 4 lbs of plums for taste etc....the extra sugar i would add i can handle..just thinking more towards "Use 1 quart of juice and add water to make up a gallon...then add sugar for expected abv" (just as an example)

[tater]

Ive made it both ways from freash and canned fruit. The canned will have a bit differnt taste(taste like cooked fruit ). Just figure from site what sugar content from can and adjust recipe from that.

[noobsauce]

ty ty for answer..going to try using prune juice though...as there arent any plums to be had anywhere here atm. Gonna weigh it and use it by weight kinda = to plums and adjust sugar..will see how it goes.