Depreciation is an accounting method of allocating the cost of a tangible asset over its useful life and is used to account for declines in value. Businesses depreciate long-term assets for both tax and accounting purposes. For tax purposes, businesses can deduct the cost of the tangible assets they purchase as business expenses; however, businesses must depreciate these assets according to IRS rules about how and when the company can take the deduction.
Depreciation is often a difficult concept for accounting students as it does not represent real cash flow. Depreciation is an accounting convention that allows a company to write off an asset’s value over time, but it is considered a non-cash transaction.
For accounting purposes, depreciation expense does not represent a cash transaction, but it shows how much of an asset’s value the business has used over a period. For example, if a company buys a piece of equipment for $50,000, it can either write the entire cost of the asset off in year one or write the value of the asset off over the assets 10-year life. This is why business owners like depreciation. Most business owners prefer to expense only a portion of the cost, which artificially boosts net income. In addition, the company can scrap the equipment for $10,000, which means it has a salvage value of $10,000. Using these variables, the analyst calculates depreciation expense as the difference between the cost of the asset and the salvage value, divided by the useful life of the asset. The calculation in this example is ($50,000 – $10,000) / 10, which is $4,000.
This means the company’s accountant does not have to write off the entire $50,000, even though it paid out that amount in cash. Instead, the company only has to expense $4,000 against net income. The company expenses another $4,000 next year and another $4,000 the year after that, and so on, until the company writes off the value of the equipment in year 10.
Causes of Depreciation
Depreciation is a ratable reduction in the carrying amount of a fixed asset. Depreciation is intended to roughly reflect the actual consumption of the underlying asset, so that the carrying amount of the asset has been greatly reduced to its salvage value by the time its useful life is over. But why do we need depreciation at all? The causes of depreciation are:
(i) Wear and Tear
Any asset will gradually break down over a certain usage period, as parts wear out and need to be replaced. Eventually, the asset can no longer be repaired, and must be disposed of. This cause is most common for production equipment, which typically has a manufacturer’s recommended life span that is based on a certain number of units produced. Other assets, such as buildings, can be repaired and upgraded for long periods of time.
Some assets have an extremely short life span. This condition is most applicable to inventory, rather than fixed assets.
(iii) Usage rights
A fixed asset may actually be a right to use something (such as software or a database) for a certain period of time. If so, its life span terminates when the usage rights expire, so depreciation must be completed by the end of the usage period.
(iv) Natural resource usage
If an asset is natural resources, such as an oil or gas reservoir, the depletion of the resource causes depreciation (in this case, it is called depletion, rather than depreciation). The pace of depletion may change if a company subsequently alters its estimate of reserves remaining.
Some equipment will be rendered obsolete by more efficient equipment, which reduces the usability of the original equipment.
A variation on the depreciation concept is the destruction of or damage to equipment. If this happens, the equipment must be written down or written off to reflect its reduced value and possibly shorter useful life. Another variation is asset impairment, where the carrying cost of an asset is higher than its market value. If impairment occurs, the difference is charged to expense, which reduces the carrying amount of the asset.
When there is damage to or impairment of an asset, it can be considered a cause of depreciation, since either event changes the amount of depreciation remaining to be recognized.