Depreciation Calculator: method, checked example and practical limits
Create straight-line or declining-balance depreciation for a finite-life asset. Book value follows an accounting allocation assumption and may differ from resale value at every reporting date.
Inputs used by this calculator
Depreciation Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Method | Straight line | Straight line · Declining balance | Chooses which Depreciation Calculator method or unknown the engine evaluates. |
| Asset cost ($) | 50,000 | 0.01 to 1000000000000 | Supplies the asset cost ($) quantity used by the published equation or result breakdown. |
| Salvage value ($) | 5,000 | 0 to 1000000000000 | Supplies the salvage value ($) quantity used by the published equation or result breakdown. |
| Useful life (years) | 5 | 1 to 100 | Supplies the useful life (years) quantity used by the published equation or result breakdown. |
| Declining rate (%) | 40 | 0.01 to 100 | Supplies the declining rate (%) quantity used by the published equation or result breakdown. |
Inputs and measurement conventions
The quantities used on this page are Method, Asset cost ($), Salvage value ($), Useful life (years), Declining rate (%). Start with values for the same situation and read the units attached to each field. The field reference below shows supported choices and numerical limits.
Tax depreciation schedules and conventions are separate. Changing useful life or residual value changes expense rather than the physical asset.
Method and equation
Allocate depreciable cost over useful life or apply a declining-balance rate while respecting the entered salvage floor.
Depreciation Calculator uses the following stated relationship: straight line=(cost−salvage)/life; declining depreciation=opening book value×rate. Its assumptions determine which question the answer can resolve.
straight line=(cost−salvage)/life; declining depreciation=opening book value×rateWorked calculation with the starting values
Method: Straight line; Asset cost ($): 50000; Salvage value ($): 5000; Useful life (years): 5; Declining rate (%): 40. These starting values give 9,000 first-year depreciation. The calculation breakdown is Total depreciable amount: 45,000; Ending book value: 5,000; Method: straight.
A $50,000 asset with $5,000 salvage over five years depreciates $9,000 annually under straight line.
Reading the answer
Book value follows an accounting allocation assumption and may differ from resale value at every reporting date.
Total depreciable amount: 45,000; Ending book value: 5,000; Method: straight. These intermediate quantities make the stated Depreciation Calculator model inspectable; they should be read together with the main answer rather than treated as independent guarantees.
Common errors and model boundaries
Tax depreciation schedules and conventions are separate. Changing useful life or residual value changes expense rather than the physical asset.
Book depreciation is not automatically the same as tax depreciation, market value or economic obsolescence.
Independent verification and next decision
Not without checking the applicable tax method, recovery period, convention and eligible deductions.
For the Depreciation Calculator method, compare straight line=(cost−salvage)/life; declining depreciation=opening book value×rate with the starting inputs and the calculation table. The linked IRS Publication 946: How To Depreciate Property and IRS: depreciation and amortization references identify the relevant definitions, conventions or domain limitations. Retain intermediate precision when comparing a manually worked answer.
Depreciation Calculator worked-example ledger
| Quantity | Example value | Role |
|---|---|---|
| Method | Straight line | Entered assumption |
| Asset cost ($) | 50000 | Entered assumption |
| Salvage value ($) | 5000 | Entered assumption |
| Useful life (years) | 5 | Entered assumption |
| Declining rate (%) | 40 | Entered assumption |
| Main answer | 9,000 first-year depreciation | Calculated from the starting inputs |
| Total depreciable amount | 45,000 | Intermediate or contextual output |
| Ending book value | 5,000 | Intermediate or contextual output |
| Method | straight | Intermediate or contextual output |
Frequently asked questions
Can the schedule be used as a tax filing table?
Not without checking the applicable tax method, recovery period, convention and eligible deductions.
Which relationship does the Depreciation Calculator use?
Allocate depreciable cost over useful life or apply a declining-balance rate while respecting the entered salvage floor. The displayed relationship is straight line=(cost−salvage)/life; declining depreciation=opening book value×rate.
What do the starting values produce in the Depreciation Calculator?
Method: Straight line; Asset cost ($): 50000; Salvage value ($): 5000; Useful life (years): 5; Declining rate (%): 40. These starting values give 9,000 first-year depreciation. The calculation breakdown is Total depreciable amount: 45,000; Ending book value: 5,000; Method: straight.
How should I interpret this Depreciation Calculator answer?
Book value follows an accounting allocation assumption and may differ from resale value at every reporting date.
Which input mistake most affects the Depreciation Calculator?
Tax depreciation schedules and conventions are separate. Changing useful life or residual value changes expense rather than the physical asset.
What is outside this Depreciation Calculator model?
Book depreciation is not automatically the same as tax depreciation, market value or economic obsolescence.
What to keep in mind
Book depreciation is not automatically the same as tax depreciation, market value or economic obsolescence.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.