Useful Life

The number of years, as set by the IRS, that depreciable business equipment or property is expected to be in use.

Investopedia Says:
The IRS has a depreciation table for almost every item, including computers, vehicles, and other equipment.

1. in appraisal, the economic period during which a positive cash flow is expected for the improvements.

2. in accounting and taxation, the period to depreciate a building. See Depreciation.
Example: A brick warehouse is expected to have a longer useful life than a wood-framed apartment building.

Typical operating service life of an asset for the purpose it was acquired. The term usually applies to fixed assets. The useful life used for Depreciation Accounting does not necessarily coincide with the actual physical life or any commonly recognized Economic Life. See also Depreciable Life; Depreciation.