Returns a Double specifying the depreciation of an asset for a specific time period using the double-declining balance method or some other method you specify.

Function DDB( _
   ByVal Cost As Double, _
   ByVal Salvage As Double, _
   ByVal Life As Double, _
   ByVal Period As Double, _
   Optional ByVal Factor As Double = 2.0 _
) As Double

Parameters

Cost

Required. Double specifying initial cost of the asset.

Salvage

Required. Double specifying value of the asset at the end of its useful life.

Life

Required. Double specifying length of useful life of the asset.

Period

Required. Double specifying period for which asset depreciation is calculated.

Factor

Optional. Double specifying rate at which the balance declines. If omitted, 2 (double-declining method) is assumed.

Exceptions/Errors

Remarks

The double-declining balance method computes depreciation at an accelerated rate. Depreciation is highest in the first period and decreases in successive periods.

The Life and Period arguments must be expressed in the same units. For example, if Life is given in months, Period must also be given in months. All arguments must be positive numbers.

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

Depreciation / Period = ((Cost – Salvage) * Factor) / Life

Example

This example uses the DDB function to return the depreciation of an asset for a specified period given the initial cost (InitCost), the salvage value at the end of the asset's useful life (SalvageVal), the total life of the asset in years (LifeTime), and the period in years for which the depreciation is calculated (Depr).

Sub testDDB()
   Dim InitCost, SalvageVal, MonthLife, DepYear As Double
   Dim Fmt As String
   Dim LifeTime, Depr As Double
   Const YRMOS As Integer = 12    ' Number of months in a year.
   Fmt = "###,##0.00"
   InitCost = CDbl(InputBox("What's the initial cost of the asset?"))
   SalvageVal = CDbl(InputBox("Enter the asset's value at end of its life.")
   MonthLife = CDbl(InputBox("What's the asset's useful life in months?")
   Do While MonthLife < YRMOS   ' Ensure period is >= 1 year.
      MsgBox("Asset life must be a year or more.")
      MonthLife = CDbl(InputBox("What's the asset's useful life in months?")
   Loop
   LifeTime = MonthLife / YRMOS   ' Convert months to years.
   If LifeTime <> Int(MonthLife / YRMOS) Then
      LifeTime = Int(LifeTime + 1)   ' Round up to nearest year.
   End If
   DepYear = CInt(InputBox("Enter year for depreciation calculation."))
   Do While DepYear < 1 Or DepYear > LifeTime
      MsgBox("You must enter at least 1 but not more than " & LifeTime)
      DepYear = CDbl(InputBox("Enter year for depreciation calculation.")
   Loop
   Depr = DDB(InitCost, SalvageVal, LifeTime, DepYear)
   MsgBox("The depreciation for year " & DepYear & " is " & _
   Format(Depr, Fmt) & ".")
End Sub

See Also

FV Function | IPmt Function | IRR Function | MIRR Function | NPer Function | NPV Function | Pmt Function | PPmt Function | PV Function | Rate Function | SLN Function | SYD Function | ArgumentException