Should you refinance your mortgage? Whenever interest rates drop, the appeal of refinancing your mortgage grows. But it's important to know the real costs - and potential savings - before making a move.

Instructions. Just fill in the non-colored boxes with the requested information. As you tab or mouse-click through the boxes, your results will appear automatically in the colored boxes. You can change any of your entries, in case you want to try several different scenarios, but you must tab or mouse-click to another box to update your results.