The best way to answer this question is to play around a little with some useful online calculators. Check out the calculators at
www.finaid.com for starters. You may also want to play with the calculator at
www.paycheckcity.com to give you a sense of what your take home pay will be for a given gross salary.
In round numbers, if you borrow $30-35K during your first year of medical school, continue similarly through medical school, and enter three years of forbearance during residency, your total capitalized debt will be around $175K. (If you are borrowing more than this for your first year, that total debt number of $175K is bogus and may be based on a class that graduated already. Medical school costs increase at a rate that outpaces inflation every year!) Anyway, if you're only borrowing $35K next year, you will likely have only Stafford loans (at 6.8%). In a 10 year level repayment plan, your monthly payments will be around $2K/month. If you pay off your debt over 30 years, as suggested above, your payments will be more like $1100/month.
Only you can determine how quickly this debt can be repaid on a given salary. Obviously, if you live like a homeless person, moonlight like crazy, or have a spouse with a high income, you can pay it off quickly, especially if you are motivated to do so. If you have several children and a stay-at-home spouse while living in a high cost of living area (i.e., the other extreme) ... it may take the whole 30 years.
