Assets supports five depreciation methods:
Straight line
Requires the Posting Frequency, Years, or Percentage fields. Removes a set percentage from the Bought Value each year or month. Always reduces the Net Book Value to zero unless a residual value is entered. A confirmation prompt appears if you select any method other than Straight Line.
Reducing balance
Requires the Posting Frequency and Yearly Percentage. Removes a set percentage from the Net Book Value each time a posting occurs. Never reduces the Net Book Value to zero.
Sum of digits
Requires the number of years (the expected useful life of the asset). Calculates the sum of all the years the asset will be open and depreciates by a reducing fraction. For example, over 5 years the annual depreciation amounts are 5/15, 4/15, 3/15... of the Bought Value. Always reduces the Net Book Value to zero unless a residual value is entered.
Period ratio
Allocates a proportion of total depreciation to each period. Only available when using 12 periods per year. Set the proportions in Assets → Options → Asset Options on the Periods tab. Proportions must add up to 52.
None
No depreciation is calculated.