How long does depreciation last?

Depreciation (the process of deducting the purchase price of a fixed asset over several accounting periods) depends on estimates of the useful life of each asset and its worth upon disposal. Since it is hard to predict exactly how long each asset will be used in your business, you must approximate how long an asset will contribute to revenue generation. There are also rules about when you can begin depreciation, and when you must stop. These generally accepted accounting principles help standardize the process of depreciation and ensure that it's done correctly.