Straight line depreciation:

It is the simplest and most often used technique, in which the company estimates the salvage value of the assets at the end of the period during which it will be used to generate revenues and will expense a portion of original cost is equal increments over that periods. The salvage value is an estimate of the value of the assets at the time it will sold or disposed of; it may be zero or even negative.

Declining-balance method

Depreciation methods that provide for a higher depreciation charge in the first year of an assets life and gradually decreasing charges in subsequent year are called accelerated depreciation method

Activity depreciation

It is an method are not based on time, but on the level of the activity. This could be miles driven for a vehicle or a cycle count for a machine.When the assets acquired, Its life is estimated in term of this level of activity

Units-of-production depreciation method

Under the unit of production method, useful life of the assets is express in terms of the total number of units expected to be produced:

Annual depreciation expense =cost of fixed asset-residual value /estimated total production*actual production