Depreciation is the same for each year of the assets useful life.
It is measured solely by the passage of time.
Advantage: Fixed asset is shown at current or realisable value.
Depreciation for any period = (Initial cost of asset-Salvage value) / Useful Years
Initial cost of asset = $30,000
Salvage value = $500
Years of Useful Life = 5 years
= (30,000 - 500 ) / 5
= $ 5,900