What is Depreciation in Accounting?
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What is Depreciation in Accounting?

Updated: Jan 6, 2023

Depreciation is the process of allocating the cost of a tangible asset over its useful life. It is a non-cash expense that is used to reduce the value of the asset on a company's balance sheet. The purpose of depreciation is to reflect the fact that an asset's value decreases over time due to wear and tear, obsolescence, and other factors.


Depreciation is a way of spreading the cost of an asset over the period of time that it is used, rather than expensing the entire cost in the year the asset is purchased. It is used to match the expense of the asset with the revenue it generates, which is known as the matching principle.


There are several methods of calculating depreciation, including straight-line depreciation, declining balance depreciation, and sum-of-the-years'-digits depreciation. The choice of method depends on the nature of the asset and the company's accounting policies.


Depreciation is a important concept in accounting and is often used to make financial statements more accurate and representative of a company's true financial position.


What is Depreciation Expense?


Depreciation expense is the amount of the cost of a tangible asset that is allocated to a specific accounting period as an expense. It is a non-cash expense that is used to reduce the value of the asset on a company's balance sheet.


Depreciation expense is calculated using one of several methods, such as straight-line depreciation, declining balance depreciation, or sum-of-the-years'-digits depreciation. The chosen method depends on the nature of the asset and the company's accounting policies.


For example, consider a company that purchases a machine for $100,000 and expects it to have a useful life of 10 years. Using the straight-line method of depreciation, the company would allocate $10,000 of the cost of the machine to each of the 10 years of its useful life, resulting in annual depreciation expense of $10,000.


Depreciation expense is recorded in the income statement as a reduction of the cost of goods sold or as a separate line item in the operating expenses section. It is important to note that depreciation expense is a non-cash expense, meaning that it does not involve the exchange of cash.


Causes of Depreciation


There are several causes of depreciation, including:

  1. Wear and tear: Over time, assets tend to deteriorate and lose value due to normal wear and tear. This can include physical damage, such as scratches or dents, or mechanical failure due to use.

  2. Obsolescence: Assets may become obsolete or outdated due to technological advances, changes in consumer preferences, or other factors. This can decrease the value of the asset and result in depreciation.

  3. Physical deterioration: Assets that are exposed to the elements, such as buildings or vehicles, may suffer from physical deterioration over time due to weathering, corrosion, or other factors.

  4. Lack of demand: If demand for a particular asset decreases, its value may also decrease, leading to depreciation.

  5. Economic conditions: Economic downturns or other market conditions can affect the value of assets and result in depreciation.

It is important to note that depreciation is a non-cash expense and does not necessarily reflect the actual cash value of an asset. It is used to allocate the cost of an asset over its useful life and is a way of spreading the expense of the asset over the period of time that it is used.


Types of Depreciation


There are several types of depreciation methods that can be used to allocate the cost of a tangible asset over its useful life. The choice of method depends on the nature of the asset and the company's accounting policies. Some common types of depreciation methods include:

  1. Straight-line depreciation: This is the most common method of depreciation and is the simplest to calculate. Under this method, the cost of the asset is divided by the number of years of its useful life to determine the annual depreciation expense.

  2. Declining balance depreciation: This method calculates depreciation expense by applying a fixed percentage to the asset's book value (cost minus accumulated depreciation) each year. The result is a higher depreciation expense in the earlier years of the asset's life and a lower expense in the later years.

  3. Sum-of-the-years'-digits depreciation: This method calculates depreciation expense by multiplying the asset's book value by a fraction, with the numerator equal to the number of years of the asset's useful life remaining and the denominator equal to the sum of the number of years of the asset's useful life.

  4. Units-of-production depreciation: This method calculates depreciation expense based on the number of units of output produced by the asset. It is often used for assets that are expected to have a consistent level of usage over their useful lives.

  5. Double-declining balance depreciation: This method is similar to the declining balance method, but the depreciation rate is double the straight-line rate. It results in a higher depreciation expense in the earlier years of the asset's life and a lower expense in the later years.


Depreciation Examples


Here are examples of how to calculate depreciation using the methods listed above:


Straight-line depreciation:

  • Asset cost: $100,000

  • Useful life: 10 years

  • Annual depreciation expense: ($100,000 / 10 years) = $10,000 per year

Declining balance depreciation:

  • Asset cost: $100,000

  • Salvage value: $10,000

  • Useful life: 10 years

  • Depreciation rate: 50%

  • Annual depreciation expense: ($100,000 - $10,000) x 50% = $45,000 in the first year

  • Book value at the end of year 1: $100,000 - $45,000 = $55,000

  • Annual depreciation expense: ($55,000 - $10,000) x 50% = $22,500 in the second year

Sum-of-the-years'-digits depreciation:

  • Asset cost: $100,000

  • Salvage value: $10,000

  • Useful life: 10 years

  • Depreciation rate: (10 years / (1 + 2 + 3 + ... + 10)) = 10/55 = 18.18%

  • Annual depreciation expense: ($100,000 - $10,000) x 18.18% = $16,364 in the first year

  • Book value at the end of year 1: $100,000 - $16,364 = $83,636

  • Annual depreciation expense: ($83,636 - $10,000) x 18.18% = $13,697 in the second year

Units-of-production depreciation:

  • Asset cost: $100,000

  • Salvage value: $10,000

  • Useful life: 10 years

  • Expected units of output: 100,000 units

  • Depreciation rate: ($100,000 - $10,000) / 100,000 units = $0.90 per unit

  • Actual units of output in year 1: 10,000 units

  • Annual depreciation expense: $0.90 x 10,000 units = $9,000 in the first year

  • Book value at the end of year 1: $100,000 - $9,000 = $91,000

  • Actual units of output in year 2: 12,000 units

  • Annual depreciation expense: $0.90 x 12,000 units = $10,800 in the second year


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