Economic life is the period an entity expects to be able to use an asset, assuming a normal amount of usage and maintenance. Different from physical life, economic life is used to determine how long a capital investment, or investment in real estate, will be useful towards the operations of a business. Economic life doesn’t just refer to a predetermined amount of time, and can be applied to other forms of measurement such as mileage. For example, one may refer to an automobiles economic life as 200,000 miles, instead of 15 years.