Two caveats about this calculator:

1) If you think you need to earn $100,000 to comfortably pay $1,000 a month then you must have an extraordinarily extravagant lifestyle. Assume 40% effective tax rate: $100,000 becomes $60,000 per year which is $5,000 per month. Excluding savings, my current cost of living (Food, rent, entertainment, and all other expenses) is less than $1,800. If I earned $5,000 take home every month, that would leaves $3,200 of extra, "discretionary" income. Even if I put $1,000 of that straight into the bank, I would still be left with $2,200 to spend on loan payments. And my $1,800 per month budget is VERY comfortable. It would be easy to live on far less than that if you didn't eat out and go to the bars as often as I do.

2) This calculator does not take into account compounding interest while you're in school. It assumes a single lump sum borrowed at a fixed interst rate with payments beginning immediately. If you borrow $90,000 over three years, most of that will NOT be subsidized by the government and interest will compound from the day you sign the paperwork for the loan to cover your first semester's tuition. I have a spreadsheet that I used to make much more accurate calculations and determined that I would be $160,000 in debt at graduation after borrowing $135,000 to cover tuition and cost of living for three years. That's $25,000 in interest that's compounded during school alone.