Visual Basic 2005 in a Nutshell (In a Nutshell (OReilly))

Class

Microsoft.VisualBasic.Financial

Syntax

DDB(cost, salvage, life, period[, factor])

cost (required; Double)

The initial cost of the asset.

salvage (required; Double)

The value of the asset at the end of life.

life (required; Double)

Length of life of the asset.

period (required; Double)

Period for which the depreciation is to be calculated.

factor (optional; Double)

The rate at which the asset balance declines. If omitted, 2.0 is used by default (double-declining method).

Description

The DDB function returns a Double representing the depreciation of an asset for a specific time period. This is done using the double-declining balance method or another method that you specify using the factor argument.

The double-declining balance method calculates depreciation at a differential rate, which varies inversely with the age of the asset. Depreciation is highest at the beginning of an asset's life and declines over time.

Usage at a Glance

• The life and period arguments must be specified in the same time units. For instance, both must be expressed in units of months, or both must be years.

• All arguments must be positive numbers.

• The double-declining balance depreciation method calculates depreciation at a higher rate in the initial period and a decreasing rate in subsequent periods.

• The DDB function uses the following formula to calculate depreciation for a given period:

  depreciation / period = ((cost - salvage) * factor) / life

Example

Dim initialCost As Double = 2000 Dim salvageValue As Double = 50 Dim usefulLife As Double = 12 Dim totalDepreciation As Double = 0 Dim periodScan As Double Dim thisPeriodDepr As Double For periodScan = 1 To 12 thisPeriodDepr = DDB(initialCost, salvageValue, _ usefulLife, periodScan) totalDepreciation += thisPeriodDepr Console.WriteLine("Month " & periodScan & ": " & _ thisPeriodDepr) Next periodScan Console.WriteLine("Total: " & totalDepreciation)