The VDB function calculates the depreciation of an asset for a given time period based on a variable declining balance depreciation method.
Syntax
=VDB(cost,salvage,life,start_period,end_period,[factor],[no_switch])
Arguments
Argument  Description  

cost  The original cost of the asset  
salvage  The salvage value after the asset has been fully depreciated  
life  The useful life of the asset or the number of periods that you will be depreciating the asset  
start_period  The starting period that you wish to calculate the depreciation for. Use the same units as for the life  
end_period  The ending period that you wish to calculate the depreciation for. Use the same units as for the life  
[factor]  Optional. It is the rate to use for the declining balance. If this parameter is omitted, the VDB function will assume a [factor] of 2  
[no_switch]  Optional. It can either be a value of TRUE or FALSE. If the [no_switch] parameter is omitted, the VDB function will assume a [no_switch] value of FALSE

Examples
A  B  C  D  

1  Data  
2  $30,000.00  Asset cost  
3  $3,000.00  Salvage value  
4  10  Life (years)  
5  
6  Formula  Result  Notes  
7  =VDB(A2,A3,A4*365,0,1)  $16.44  First day’s depreciation. Excel automatically assumes that factor is 2  
8  =VDB(A2,A3,A4*12,0,1)  $500.00  First month’s depreciation  
9  =VDB(A2,A3,A4,0,1)  $6,000.00  First year’s depreciation  
=VDB(A2,A3,A4*12,6,18)  $4,953.83  Depreciation between the sixth month and the eighteenth month  
10  =VDB(A2,A3,A4*12,6,18,1.5)  $3,897.61  Depreciation between the sixth month and the eighteenth month using a factor of 1.5 instead of the doubledeclining balance method  
11  =VDB(A2,A3,A4,,5)  $20,169.60  Depreciation between purchase and end of year 5 
Common Function Error(s)
Problem  What went wrong  

#VALUE!  Occurs if any of the supplied arguments are not numeric values  
#NUM!  Occurs if either:

When calculating the depreciation of an asset, it is common to use an accelerated depreciation calculation, in which the calculated value of an asset is reduced by a larger amount during the first period of its lifetime, and smaller amounts during subsequent periods.
One of the most popular accelerated depreciation methods is the Double DecliningBalance Method, in which the straightline depreciation rate is doubled.
The Excel VDB function uses the Double DecliningBalance Method by default. However, the function allows you to specify a factor to multiply the straight line depreciation by, therefore allowing the user to determine the rate of depreciation.