You see and hear the ads everywhere: Refinance your mortgage and save money. Often, that's good advice. But not always. Before committing to refinancing, it's best to figure out how long it will take to break even when all costs are considered. This calculator factors in your current interest rate, the potential new rate, closing costs and how long you plan to stay in your home. In the end, you'll have a good idea about whether it makes sense to refinance your current mortgage.