The SYD function returns the depreciation of an asset for a given time period based on the sumofyears’ digits depreciation method.
Syntax
=SYD(cost,salvage,life,per)
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 
per  The period that you wish to calculate the depreciation for. Use the same units as for the life 
Examples
A  B  C  D  E  

1  Data  
2  $30,000.00  Initial cost  
3  $3,000.00  Salvage value  
4  10  Life (years)  
5  
6  Formula  Result  Depreciated Value  Notes  
7  =SYD(A2,A3,A4,1)  $4,909.09  $25,090.91  Yearly depreciation allowance for the first year  
8  =SYD(A2,A3,A4,5)  $2,945.45  $10,363.64  Yearly depreciation allowance for the fifth year; depreciated value = initial cost minus 5 years accrued depreciation  
9  =SYD(A2,A3,A4,10)  $490.91  $3,000.00  Yearly depreciation allowance for the tenth year; depreciated value = initial cost minus 10 years accrued depreciation 
Common Function Error(s)
Problem  What went wrong  

#VALUE!  Occurs if any of the supplied values are nonnumeric  
#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 popular accelerated depreciation method is the sumofyears’ digits depreciation method, which calculates depreciation using the following equation: