# DDB function

Returns a Double specifying the depreciation of an asset for a specific time period by 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 the initial cost of the asset.
salvage Required. Double specifying the value of the asset at the end of its useful life.
life Required. Double specifying the length of useful life of the asset.
period Required. Double specifying the period for which asset depreciation is calculated.
factor Optional. Variant specifying the 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
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) & "."
``````