The difference between the value of the property and the total amount of any debts secured by liens on the property. The "value" of the property will depend upon the context in which the property is sold.  A sale from a seller not obligated to sell to a buyer not obligated to buy will generate the highest value (often referred to as "fair market value"). A forced sale, such as an execution sale, a foreclosure sale, or a bankrutpcy sale, will generate lower values.   Until a sale, value, and hence equity, can only be estimated.  Appraisers specialize in giving such estimates.