The Excel SLN Function

Straight Line Depreciation

Straight line depreciation is the most simple way of calculating the depreciation of an asset.

This method simply subtracts a fixed amount from the value of an asset during each period of the asset's lifetime. Therefore, the straight line depreciation for one period is calculated by the following equation:

SLN Function Equation


  • cost = initial cost of the asset (at start of period 1);
  • salvage = final value of the asset at the end of its lifetime;
  • life = number of periods over which the depreciation occurs.
Related Functions:
DB Function
DDB Function

Function Description

The Excel SLN function calculates the straight line depreciation of an asset for one period.

The syntax of the function is:

SLN( cost, salvage, life )

where the arguments are:

cost-The initial cost of the asset.
salvage-The value of the asset at the end of the depreciation.
life-The number of periods over which the asset is to be depreciated.

SLN Function Examples

In the example spreadsheet below, the SLN function is used to calculate the yearly or monthly depreciation of assets with different cost, salvage and lifetime values.

1Straight Line Depreciation:
2=SLN( 10000, 1000, 5 )Initial cost = $10,000; salvage = $1,000; lifetime = 5 yrs
3=SLN( 500, 100, 8 )Initial cost = $500; salvage = $100; lifetime = 8 yrs
4=SLN( 1200, 200, 6 )Initial cost = $1,200; salvage = $200; lifetime = 6 mths
1Straight Line Depreciation:
2$1,800.00- Yearly depreciation = (10000 - 100) / 5 = $1,800
3$50.00- Yearly depreciation = (500 - 100) / 8 = $50
4$166.67- Monthly depreciation = (1200 - 200) / 6 = $166.67

Further examples of the Excel SLN function are provided on the Microsoft Office website.

Excel SLN Function Errors

If you get an error from the Excel SLN Function, this is likely to be one of the following:

Common Errors
#DIV/0!-Occurs if the supplied life argument is equal to 0.
#VALUE!-Occurs if any of the supplied arguments are non-numeric.