### ZIMSEC O Level Principles of Accounts Notes: Calculating/Estimating depreciation: The straight line method

- As already pointed out there are number of ways in which depreciation can be calculated
- The straight line method is merely one of these methods
- It is the most popular and simplest method of calculating depreciation there is
- First the cost of the asset is ascertained
- which is easy if the asset is purchased by the business it’s cost is the total cost expended in acquiring the asset
- Then the estimated useful life of the asset is determined/estimated
- Finally the estimated residual value i.e. the value at which we expect to sell the asset at the end of it’s useful life is determined/estimated
- The yearly depreciation is then calculated using the formula:
- \mathrm{\dfrac{Cost -Residual \quad Value}{Useful \quad Life\quad in\quad years}}
- The amount depreciation yielded by this formula is then charged each year in the Income Statement until the asset is disposed of

#### Simple example

- On 1 January 20×7 J Banda bought a second hand lorry for $10 000
- The lorry is expected to be used in the business for 5 years whereupon it will be sold for an estimated $2 000

Required

- Calculate the yearly depreciation for the lorry to be shown in the books of J Banda

#### Solution

- First ascertain the cost which in this case is clearly $10 000
- Then determine the useful life which is 5 years
- Then residual value which in our case is $2 000
- Depreciation would be
- \dfrac{10000 -2000}{5}
**$1 600/per year**

#### Advantages

- It is simple to calculate and implement
- It is simple to understand even to non accountants
- The same amount of depreciation is charged to the Income Statement every year allowing for easier year on year comparison of profits
- The method can be applied to all manner of assets
- It is a widely accepted method of depreciation

#### Disadvantages

- Does not accurately reflect how usage of the asset varies from period to period
- Is not suitable for rapidly evolving assets that are susceptible to change in technology
- Does not reflect the increasing maintenance cost of the the asset in later years

To access more topics go to the Principles of Accounting Notes.