The amount at which an asset is recorded in a company's accounts (literally, the value shown in the books). Initial book value recorded is usually the cost of acquisition and may include incidental costs. Over time, this amount may be depreciated, producing a lower amount. Book value may not, therefore, necessarily reflect an asset's current market value but it may do so if the asset is revalued to fair value at each accounts date (in which case, such amount then becomes book value).