Summary

The Excel DDB function returns the depreciation of an asset for a specified period using the double-declining balance method, or another declining-balance method if a custom factor is supplied. Microsoft documents the optional factor argument for exactly that reason: the function is not limited to double-declining logic unless the factor is 2.

This makes DDB an accelerated depreciation function. Earlier periods receive larger depreciation charges because the method applies the factor to the declining carrying value instead of spreading the depreciable base evenly.

DDB is therefore useful when the model should emphasize early-period depreciation more strongly than straight-line depreciation and often more strongly than the fixed-rate DB method.

Syntax

=DDB(cost, salvage, life, period, [factor])

cost is the original asset cost, salvage is the ending residual value, life is the total number of periods, and period is the period being calculated. The optional factor controls how aggressively depreciation is accelerated; if omitted, Excel uses 2, which is the standard double-declining balance method.

Changing the factor changes the shape of the depreciation schedule. Higher factors increase early-period charges and reduce book value more quickly.

Arguments

• cost - The original asset cost.
• salvage - The expected residual value at the end of the asset life.
• life - The number of depreciation periods.
• period - The specific period to calculate.
• factor - [Optional] The acceleration factor. Defaults to 2.

The life and period arguments should use the same unit. If life is measured in years, the selected period should also be a year number unless the schedule has been rebuilt on a different basis.

DDB vs Other Functions

DDB belongs to the same depreciation family as SLN, DB, and SYD, but it is one of the more aggressive methods because of the factor-based declining balance approach.

Use DDB when the model needs a clearly accelerated book value decline and the factor itself is part of the analytical choice.

Using the DDB Function

DDB is most useful when earlier periods should absorb more of the depreciation burden. That produces a steep initial drop in book value and a tapering expense pattern as the asset ages.

It is also helpful for method comparison. Looking at DDB beside DB, SLN, or SYD makes it easier to see whether the chosen depreciation policy is merely accelerated or aggressively front-loaded.

• Use DDB when early-period depreciation should be emphasized strongly.
• Keep the period unit aligned across life and period.
• Review the factor carefully, because it materially changes the shape of the schedule.

Example 1 - Double-Declining Balance

This formula returns first-year depreciation using the standard factor of 2. It shows the default double-declining balance approach, where depreciation is accelerated relative to straight-line depreciation.

=DDB(10000,1000,5,1,2)

Example 2 - Highly Accelerated (Factor 3)

Raising the factor to 3 increases the first-period depreciation further. This example is useful because it shows that DDB is not just one fixed method; it can represent different levels of acceleration depending on the factor chosen.

=DDB(10000,1000,5,1,3)

Example 3 - Threshold vs Straight Line

This comparison asks whether the first-period DDB charge is greater than $2,000. It is a simple review test for identifying assets whose accelerated first-year depreciation is materially above a benchmark.

=DDB(10000,1000,5,1)>2000

Example 4 - Remaining Book Value

Subtracting the year-1 DDB amount from cost gives the carrying value after the first period. Because DDB is aggressively front-loaded, this remaining value is lower than it would be under a straight-line schedule.

=10000-DDB(10000,1000,5,1)

Conclusion Recap

• Summary: DDB returns depreciation for one period using a declining-balance factor, with 2 as the default.
• Syntax: =DDB(cost,salvage,life,period,[factor]).
• Core setup: Keep period units consistent and review the factor before interpreting the schedule.
• Best use: Accelerated depreciation analysis, method comparison, and early book value modeling.