Summary: You may have heard about interest rates falling and are debating whether to refinance your mortgage loan. But is a lower interest rate enough reason to refinance? To know for sure you need to calculate the money you'll save by refinancing.

Try using an online mortgage calculator to determine your options for refinancing.

Q: Should I refinance? I currently have 15 years left on my 30-year mortgage at 6.5 percent interest rate. The loan balance is $116,991.

A: Don't start shopping around for a refinance just yet. You're mostly paying off the balance of your loan. It would only make sense to refinance if you can get a 10-year loan at 4.5 percent (with very few fees). Then, you're saving 5 years of payments. (It could be 4 years of payments, but the savings should be significant).

For example: If you financed a loan amount of $117,000 at an interest rate of 4.5 percent over 15 years, the monthly payment would be $895.04. But if you financed a loan amount of $117,000 at 4.5 percent over a period of 10 years, the monthly payment would be $1,212.57.

If $1,212.57 is the same as what you're paying now or less, then you should refinance because you will save 5 years of payments.

You can play around with the numbers yourself at many online calculators. I calculated these at eloan.com. But you need to keep in mind that many lenders have raised their fees and costs to refinance. If the costs to refinance are too high or the rate you get isn't low enough, you may be better off with your current loan.