Steven Brand 
Steven Brand
Licensed Mortgage Loan Originator NMLS# 261849, iLoan Home Mortgage
Saint Paul, Minnesota
Licensed Mortgage Loan Originator NMLS# 261849, iLoan Home Mortgage
11 months ago
I would recommend you confirm with a good local Financial Planner if working hard to pay it off in 5 years is the best bet for you first of all. You may really be surprised to find that in certain situations there are other options to help you achieve your underlying short/long term goals.
But to just answer your question... I'd confirm that your interest rate was close to current rates and then run "amortization charts" for you to compare paying extra on your current mortgage vs getting a new loan and show you the total interest you would pay in both scenarios.
Depending on your current situation (with home owners insurance and property taxes)... paying about 30% of your monthly income on your total housing payment could pay off your home in just about 5 yrs.