Uhh, $0. Most of the time when people ask for money, it's only in increments of $5-10 so I never require them to pay me back. If they ask for more, it'll depend on how close I am to that person. For example, I wouldn't have any problem with certain people borrowing a couple hundred (and some of them I won't require them to pay me back), but if I'm not very close with them or they take advantage of the situation, I just pretend I don't have anything to give them.