Summary

The Excel DB function returns the depreciation of an asset for a specified period using the fixed-declining balance method. Microsoft documents DB as a declining-balance depreciation function, which means earlier periods usually receive larger charges than later ones.

Unlike straight-line depreciation, DB does not spread the depreciable base evenly. It applies a fixed rate to the asset's declining book value. Microsoft also notes an important detail: the depreciation rate used by DB is rounded to three decimal places, which can affect schedules slightly.

DB is therefore useful when the model should recognize faster depreciation early in the asset life but still follow a structured declining-rate method rather than a flat annual charge.

Syntax

=DB(cost, salvage, life, period, [month])

cost is the original asset cost, salvage is the value at the end of the asset life, life is the total number of periods, and period is the period being calculated. The optional month argument specifies the number of months in the first year and defaults to 12 if omitted.

That optional month argument matters when the first year is shorter than a full 12 months. It changes the first-period depreciation and also affects the schedule's final period.

Arguments

• cost - The asset's original 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.
• month - [Optional] Number of months in the first year. Defaults to 12.

The period unit should stay consistent throughout the model. If life is measured in years, the selected period should also be a year number unless the schedule has been converted to another unit everywhere else.

DB vs Other Functions

DB is one of several depreciation functions, but it sits between straight-line and more aggressive accelerated methods.

Use DB when the schedule should decline over time, but the chosen method is specifically the fixed declining-balance approach documented by Excel.

Using the DB Function

DB is most useful in asset schedules where earlier periods should carry more depreciation than later ones. This can make the early book value decline faster than under straight-line depreciation.

It is also worth checking the full schedule rather than a single output. Because the rate is fixed and applied to a falling balance, the pattern is driven by compounding logic rather than by an equal-per-period allocation.

• Use DB when a fixed declining-balance method is required.
• Keep the period unit consistent and use the optional month argument only when the first year is partial.
• Review the book value path, because the value of DB lies in the schedule shape as much as the individual period result.

Example 1 - First-Year Depreciation

This formula returns the first year's depreciation for a $10,000 asset with $1,000 salvage over 5 years. Because DB front-loads the schedule, the first-period charge is larger than the later-period charges for the same asset.

=DB(10000,1000,5,1)

Example 2 - Final-Year Audit

Calculating year 5 shows how much the depreciation charge has tapered by the end of the schedule. This is useful when comparing DB to SLN or DDB and seeing how differently the methods shape expense recognition.

=DB(10000,1000,5,5)

Example 3 - High-Value Asset Check

This comparison turns the first-period depreciation into a review test. It can help flag assets whose early declining-balance expense is above a budget or reporting threshold.

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

Example 4 - Remaining Book Value

Subtracting the year-1 DB charge from cost gives the carrying value after the first period. That book value becomes the base from which later declining-balance charges continue to fall.

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

Conclusion Recap

• Summary: DB returns depreciation for one period using the fixed declining-balance method.
• Syntax: =DB(cost,salvage,life,period,[month]).
• Core setup: Keep the period unit consistent and use month only when the first year is partial.
• Best use: Declining-balance asset schedules, method comparison, and book value analysis.