If you’re wondering whether or not you’re in an underwater mortgage, the key is to understand your loan to value, or LTV, ratio. The LTV reflects how much you owe as a percentage of the total value of your house. So, for example, if you originally took out a $130,000 mortgage on a house that was appraised at $150,000, your LTV ratio would be 87%. In other words, you would then owe 87% of what the house was actually worth-a win for you once the mortgage was paid off, provided that the property value didn’t change. Which, of course, never happens, does it?
Read more here: LTV – The Key to the Underwater Mortgage