There will usually be at least 4-6 inches of excess that you cut with snips, depending on the string and the headstock design (3+3, six on top, six on the bottom, etc). On the thickest string and the other wound strings, two full winds should be sufficient (assuming your guitar doesn’t have locking pegs, where a screw holds the string in place). On the plain steel strings, 4 or more winds is good. Either way, you WILL have a minimum of a few inches to trim from the end if you’ve done it right.
Get a string winder. They’re dirt cheap and will save you some tears.