DB – Declining Balance method of depreciation
Syntax:
=DB(cost,salvage,life,period,[month])
Cost: cost of the asset
salvage: residual value of asset at the end of its useful life
life: useful life of asset
period: accounting period for which depreciation is to be calculated
month (optional): month of the year in which asset was purchased. It is optional. If mentioned the calculation will be done considering the month of purchase on prorata basis. If not mentioned Excel assumes the asset was purchased at the beginning of the period.
Example:
Step 1: Open tab named DB and observe the data provided.
Step 2: In cell B13 put in the following formula: =DB(B7,B8,B9,B10,B11) and hit enter and it will provide the depreciation expense.
Following live excel preview provides you great way to practice this method for real:

