As students being able to budget becomes a very useful skill. The best way to avoid such this yourself is to have a clear monthly, and weekly budget, and stick to it- work out how much you have to spend each month, considering any grants, or bursaries you may be entitled to from your home or host university.
This calculator is designed to give a reasonable monthly representation of a college student's finances. This is usually run by the student just before the phone call home to say "More money please..."?