DDB Function

This page is specific to the Visual Basic for Applications (VBA) Language Reference for Office 2010.

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.

Syntax

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

The DDB function has these named arguments:

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

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).

Dim Fmt, InitCost, SalvageVal, MonthLife, LifeTime, DepYear, Depr
Const YRMOS = 12    ' Number of months in a year.
Fmt = "###,##0.00"
InitCost = InputBox("What's the initial cost of the asset?")
SalvageVal = InputBox("Enter the asset's value at end of its life.")
MonthLife = 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 = 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 = InputBox("Enter year for depreciation calculation.")
Loop
Depr = DDB(InitCost, SalvageVal, LifeTime, DepYear)
MsgBox "The depreciation for year " & DepYear & " is " & _
Format(Depr, Fmt) & "."