The Excel Amordegrc function calculates the prorated linear depreciation of an asset for each accounting period, with a depreciation coefficient applied, depending on the life of the asset. The function has been introduced into Excel for users of the French accounting system.
The syntax of the Amordegrc function is :
Where the arguments are as follows:
cost    The cost of the asset  
date_purchased    The date of purchase of the asset  
first_period    The date of the end of the first period  
salvage    The salvage value, at the end of the lifetime of the asset  
period    The number of the period over which the depreciation is to be calculated  
rate    The asset's rate of depreciation  
[basis]    An optional integer argument which specifies the financial day count basis to be is used. This may be any of the following values:  


A detailed description of the financial day count basis rules is provided on the Wikipedia Day Count Convention page 
Note that the date arguments should be entered into the function as either:
Warning:
In the following example, the Excel Amordegrc function is used to calculate the depreciation of an asset during the first period. The asset was purchased on 01Jan2011, at a cost of €150 and the first period ends on 30Sep2011. The asset depreciates at a rate of 20% per year and has a salvage value of €20. The European day count basis is used.
A  B  

1  Purchase Date:  01Jan2011 
2  First Period Date:  30Sep2011 
3  =AMORDEGRC( 150, B1, B2, 20, 1, 20%, 4 ) 
The function returns the value 42.
 i.e. the asset depreciates by €42.00 during the first period.
Note that, as recommended by Microsoft, the date arguments have been input to the above function as references to cells containing dates.
Further details and examples of the Excel Amordegrc function can be found on the Microsoft Office website.
If you get an error from the Amordegrc function, this is likely to be one of the following:
#VALUE!   
Occurs if either:

#NUM!   
Occurs if either:

#NAME?   
Occurs when Analysis ToolPak addin is not enabled in your Excel. + Show How to Do This in Excel 2003: 