Accumulated Depreciation Calculator
Enter your asset cost, salvage value, useful life, and the number of years elapsed to instantly see accumulated depreciation and current book value. Choose from three standard accounting methods: straight-line, double declining balance, or sum of years' digits. A full year-by-year depreciation schedule updates as you type.
What is accumulated depreciation?
Accumulated depreciation is the total amount of depreciation expense that has been recorded for an asset since it was placed in service. It appears on the balance sheet as a contra-asset account, meaning it reduces the gross value of the asset to arrive at its net book value. For example, a machine purchased for $50,000 with $20,000 of accumulated depreciation carries a book value of $30,000. Unlike annual depreciation expense (which flows through the income statement each period), accumulated depreciation grows larger every year until the asset is fully depreciated or disposed of. Tracking it accurately is essential for financial reporting under both GAAP and IFRS, for tax compliance, and for asset management decisions like repair-versus-replace analysis.
How to calculate accumulated depreciation: three methods
Three methods dominate business practice. Straight-line (SL) is the simplest: depreciable cost (purchase price minus salvage value) is divided evenly across the useful life. If a $50,000 machine has a $5,000 salvage value and a 10-year life, annual depreciation is $4,500 and accumulated depreciation after five years is $22,500. Double declining balance (DDB) applies a fixed rate (typically 200% / useful life, or 20% for a 10-year asset) to the remaining book value each year, front-loading expense. Sum of years' digits (SYD) assigns a declining fraction of the depreciable cost each year: the fraction for any year equals the remaining life divided by the sum of all digits (n(n+1)/2). Both DDB and SYD produce higher early-period expense and lower later-period expense compared with straight-line, which suits assets that lose value quickly or generate more economic benefit in their early years.
Straight-line vs. accelerated methods: when to use each
Straight-line is the default for most companies because it is predictable, easy to audit, and matches cost evenly to revenue when the asset contributes equally across its life, such as office furniture or buildings. Accelerated methods (DDB and SYD) better match the economic reality of assets that are most productive early in life, like technology hardware or delivery vehicles, and they also reduce taxable income sooner, improving near-term cash flow. Many companies use straight-line for financial (book) reporting and an accelerated method for tax filings, which creates a deferred tax liability on the balance sheet. The choice of method does not change total lifetime depreciation, only its timing.
Book value, salvage value, and the depreciation floor
An asset's net book value equals its original cost minus accumulated depreciation. Depreciation always stops when book value reaches the salvage value (also called residual or scrap value): you never depreciate below it. The salvage value represents what the business expects to recover by selling or scrapping the asset at the end of its useful life. A higher salvage estimate reduces annual depreciation expense; a lower estimate increases it. Reassessing salvage values periodically is good practice, particularly for technology assets whose market values can fall faster than originally projected. If an asset is sold before it is fully depreciated, any difference between the proceeds and the net book value is recognized as a gain or loss on disposal.
IRS MACRS useful life by asset class (common examples)
| Asset type | MACRS class life | Common examples |
|---|---|---|
| 3-year property | 3 years | Small tools, certain horses, tractor units |
| 5-year property | 5 years | Cars, light trucks, computers, office machinery |
| 7-year property | 7 years | Office furniture, appliances, most manufacturing equipment |
| 10-year property | 10 years | Water vessels, single-purpose agricultural structures |
| 15-year property | 15 years | Land improvements, retail motor fuel outlets |
| 20-year property | 20 years | Farm buildings, municipal water treatment plants |
| 27.5-year property | 27.5 years | Residential rental real estate |
| 39-year property | 39 years | Non-residential (commercial) real estate |
The IRS Modified Accelerated Cost Recovery System assigns standard useful lives for U.S. tax depreciation. Useful life for book depreciation may differ from tax life.
Frequently asked questions
What is the difference between depreciation expense and accumulated depreciation?
Depreciation expense is the portion of an asset's cost allocated to a single accounting period, typically one year. It is recorded on the income statement and reduces net income. Accumulated depreciation is the running total of all depreciation expense recorded for the asset since it was purchased. It sits on the balance sheet as a contra-asset account, reducing the reported value of the asset. Think of annual depreciation as a single year's charge and accumulated depreciation as the sum of all those charges to date.
Which depreciation method gives the lowest taxes?
Accelerated methods, especially double declining balance and sum of years' digits, produce larger deductions in early years, reducing taxable income sooner. In the U.S., the IRS's MACRS system is mandatory for most tax depreciation and is itself an accelerated method. Straight-line generally results in higher taxes in early years but the same total lifetime tax deduction. Always consult a tax professional for your specific situation, as bonus depreciation and Section 179 elections can allow immediate expensing of qualifying assets.
Can accumulated depreciation exceed the asset's cost?
No. Depreciation stops when the net book value reaches the salvage value. If the salvage value is zero, the asset can be fully depreciated down to $0 book value, but accumulated depreciation can never exceed the original cost. Exceeding cost would imply a negative book value, which is not permissible under standard accounting rules.
What happens to accumulated depreciation when an asset is sold?
When an asset is sold or disposed of, both the asset's gross cost and its accumulated depreciation are removed from the balance sheet. The sale proceeds are compared to the net book value: if proceeds exceed book value, a gain is recognized; if they fall short, a loss is recorded. For example, selling a fully depreciated asset for $2,000 generates a $2,000 gain if book value is zero.
How does accumulated depreciation affect the balance sheet?
Accumulated depreciation is a contra-asset account, meaning it carries a credit balance and is subtracted from the gross asset value in the property, plant, and equipment (PP&E) section of the balance sheet. The resulting figure is the net book value (also called net PP&E). A growing accumulated depreciation figure signals an aging asset base, which investors and analysts may interpret as a signal that capital expenditure is due to replace aging equipment.