The DB function is a Finance function that calculates the depreciation of an asset on the fixed-declining balance basis for a specified period. In this guide, we’re going to show you how to use the DB function and go over some tips and error handling methods.

Supported versions

  • All versions

DB Function Syntax

DB(cost, salvage, life, per, [month])


cost The initial cost of the asset.
salvage The value after the asset has been fully depreciated, salvage value.
life The number of periods over which asset is depreciated, useful life of the asset.
period Specific period to calculation depreciation for.
[month] Optional. The number of months in the first year. If omitted, it is assumed to be 12.

DB Function Examples

The DB function returns the fixed-declining balance depreciation in a specified period based on the initial cost, salvage value and the useful life. Optionally, you can provide the month number of the first year.

For example, we want to calculate the depreciation for the 2nd year of an asset with an initial cost of $20,000, a useful life of 5 years, and a salvage value of $4,000.

DB function with month

If month is entered, the function assumes that the first year only includes the number of months. In our example, we entered 7.


DB Function 01 - w/ month

You can see that the depreciation value for the first year (period) is less than the second year due to missing months in the first year.

DB function without month

You can omit the month argument if the first year includes all 12 months.


DB Function 02 - w/o month

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  • The fixed-declining balance method can be calculated manually by the following formulas:
    • rate (rounded to three decimal places):
    • First period:
    • Periods:
    • Last period:
  • The number of the period should match with the period you want to calculate the depreciation. If the life value is in years, the per value should be a year as well.

Excel Depreciation Functions

Straight line SLN
Sum-of-years' digits SYD
Double-declining balance DDB
Variable-declining balance VDB
French declining balance AMORDEGRC
French straight line AMORLINC