Straight Line Depreciation Calculator: Annual Depreciation
Work out the annual depreciation expense on a fixed asset under the straight-line method — the simplest way to spread an asset's cost across the years it will be used.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Annual depreciation |
|---|---|
| $20k cost · 10 years | $2,000.00 |
| $5k cost · 5 years | $1,000.00 |
| $120k cost · 20 years | $6,000.00 |
| $1,800 cost · 3 years | $600.00 |
How This Calculator Works
Enter the depreciable cost — asset purchase price less estimated salvage value — and the useful life in years. The calculator divides one by the other to give the annual depreciation expense, the same amount you book every year of the asset's life.
The Formula
Cost per Unit
Total Amount is the full cost or price, Quantity is the number of units it covers
Worked Example
A $22,000 piece of equipment with a $2,000 salvage value depreciated over 10 years carries a $2,000 annual depreciation expense — the same charge every year until book value drops to salvage. By year 10, accumulated depreciation equals depreciable cost.
Key Insight
Straight-line is the simplest depreciation method and the one most companies use for book accounting because it produces stable, comparable income statements. Tax depreciation in the US usually follows MACRS — an accelerated method — which is why book and tax depreciation almost always disagree.
Frequently Asked Questions
How is straight line depreciation calculated?
Subtract salvage value from asset cost to get depreciable cost, then divide by useful life in years. A $22,000 asset with $2,000 salvage over 10 years depreciates at $2,000 a year.
What is salvage value?
The estimated amount the asset will be worth at the end of its useful life — what you could sell it for, or its scrap value. Many small assets are assigned a salvage of zero.
How is this different from MACRS?
MACRS — the US tax depreciation system — accelerates depreciation into the early years, lowering taxable income sooner. Straight-line spreads the cost evenly and is used mostly for book accounting.
When does Section 179 or bonus depreciation apply?
Section 179 and bonus depreciation let businesses expense some or all of qualifying assets in the year of purchase, skipping the depreciation schedule. They are tax-only — book accounting still uses straight-line or MACRS.
Why use straight line at all?
Predictability and comparability. The same expense lands every year, which makes income statements smoother and easier to forecast. Most companies use it for book accounting even when tax depreciation runs accelerated.
Related Calculators
Methodology & Review
Annual depreciation is depreciable cost (asset cost minus salvage value) divided by useful life in years. The result is constant every year; accelerated methods (declining balance, sum-of-years' digits, MACRS) produce front-loaded schedules instead.
Written by Ugo Candido · Last updated May 17, 2026.