Depreciation: Methods and Importance
- Depreciation is the process of allocating the cost of a tangible asset over its useful life.
- It represents the reduction in the asset’s value due to factors such as wear and tear, obsolescence, or usage over time.
- Businesses use depreciation to account for asset costs in financial statements and for tax purposes.
Depreciation
The process of allocating the cost of a tangible asset over its useful life to account for wear and tear, obsolescence, or usage.
Causes of Depreciation
- Wear and tear
- As assets are used over time, gradual deterioration takes place.
- This is particularly common in physical assets like machinery, vehicles, and equipment, which experience wear through friction, aging, and exposure to the environment.
- As the asset is used, its efficiency declines, resulting in a decrease in its value.
- Obsolescence
- When an asset becomes outdated due to technological advancements or shifts in market demands.
- Even if the asset is still functioning, it may lose value as newer, more efficient alternatives become available.

Think of the old laptop or phone that you stopped using.
The Two Methods of Depreciation
1. Straight-Line Method
Straight Line Method
A depreciation method where an asset’s cost is reduced evenly over its useful life.
- The straight-line method is one of the simplest and most widely used depreciation methods.
- It allocates an equal amount of depreciation to an asset each year over its useful life.
How It Works
- The assets' cost is spread evenly across its useful life.
- The formula for calculating annual depreciation is:
$$\text{Annual Depreciation = Cost of Asset} - \frac{\text{Residual Value}}{\text{Useful Life (in years)}}$$
- Cost of Asset: The initial purchase price.
- Residual Value: The estimated value of the asset at the end of its useful life.
- Useful Life: The number of years the asset is expected to be used.
Residual Value
The estimated value of an asset at the end of its useful life, often used in depreciation calculations.
A company uses the straight-line method to depreciate its office building, which has a predictable lifespan and consistent usage.
Advantages and Disadvantages
- Advantages:
- Simple to calculate and understand.
- Provides a consistent expense each year, making budgeting easier.
- Disadvantages:
- Assumes the asset loses value evenly, which may not be realistic for all assets.


