Investment Studio > Expressions > Functions > Financial > DDB
float ddb(float initial_cost, float salvage_value, integer total_periods, integer period, float factor = 2)
Returns the depreciation of an asset for the specified period using the specified balance method.
initial_cost > 0 is the initial value of the depreciating asset.
salvage_value < initial_cost is the final value of the asset after depreciation.
total_periods >= 1 is the number of periods over which the asset depreciates (the asset's useful life).
period >= 1 is the number of the period for which the depreciation is to be returned.
factor is the depreciation rate. If omitted, it defaults to 2 (double-declining balance method).
The depreciation for each period is given by the expression
depreciation = (initial_cost - total depreciation from prior periods) * factor / total_periods
until further depreciation would reduce the remaining value to less than salvage_value. At this point, the depreciation is simply the remaining value minus salvage_value.
Example
Consider a new office computer with the following properties:
The entire annual depreciation series according to the (default) double-declining method is given by
ddb(3000, 500, 5, 1) = 1200 (full 40% depreciation)
ddb(3000, 500, 5, 2) = 720 (full 40% depreciation of remaining value)
ddb(3000, 500, 5, 3) = 432 (full 40% depreciation of remaining value)
ddb(3000, 500, 5, 4) = 148 (what's left on top of the salvage value)
ddb(3000, 500, 5, 5) = 0 (salvage value already reached)