Depreciation Calculator
Calculate asset depreciation using straight-line, declining balance, double declining, or sum-of-years digits. Full year-by-year schedule.
For informational purposes only. Not financial advice. Calculations are estimates and may not reflect your exact situation. Consult a qualified financial adviser for personalised guidance.
About Depreciation Calculator
Depreciation spreads the cost of an asset over its useful life for accounting and tax purposes. This calculator supports four standard methods - straight-line, declining balance, double declining balance, and sum-of-years digits - and produces a complete year-by-year schedule with annual expense, accumulated depreciation, and remaining book value. All calculations run in your browser.
The Four Depreciation Methods
| Method | Formula (annual) | Pattern | Best For |
|---|---|---|---|
| Straight-line | (Cost - Salvage) / Useful Life | Same amount every year | Assets that lose value evenly (furniture, buildings) |
| Declining balance | Book Value x (1 / Useful Life) x factor | Higher in early years, decreasing | Assets that lose value faster initially |
| Double declining balance (DDB) | Book Value x (2 / Useful Life) | Aggressive early depreciation | Technology, vehicles, equipment that becomes obsolete quickly |
| Sum-of-years digits (SYD) | (Cost - Salvage) x (Remaining Years / SYD Sum) | Decreasing fractions each year | Assets that are most productive when new |
Worked Example: £50,000 Machine, 5-Year Life, £5,000 Salvage
Depreciable amount = £50,000 - £5,000 = £45,000.
| Year | Straight-Line | DDB | SYD |
|---|---|---|---|
| 1 | £9,000 | £20,000 | £15,000 |
| 2 | £9,000 | £12,000 | £12,000 |
| 3 | £9,000 | £7,200 | £9,000 |
| 4 | £9,000 | £4,320 | £6,000 |
| 5 | £9,000 | £1,480 | £3,000 |
| Total | £45,000 | £45,000 | £45,000 |
All methods depreciate the same total amount (£45,000). The difference is timing - accelerated methods front-load the expense, reducing taxable income more in early years.
How Each Method Calculates
| Method | Year 1 Calculation | Notes |
|---|---|---|
| Straight-line | £45,000 / 5 = £9,000 | Same every year |
| DDB | £50,000 x (2/5) = £20,000 | Applied to book value (not depreciable amount), capped at salvage |
| SYD | £45,000 x (5/15) = £15,000 | SYD sum = 5+4+3+2+1 = 15. Year 1 fraction = 5/15 |
Common Asset Useful Life Estimates
| Asset Type | Typical Useful Life | Common Method |
|---|---|---|
| Computers and laptops | 3-5 years | DDB or straight-line |
| Office furniture | 7-10 years | Straight-line |
| Vehicles | 5-7 years | DDB (heavy early depreciation) |
| Manufacturing equipment | 7-15 years | SYD or DDB |
| Commercial buildings | 25-40 years | Straight-line |
| Software licences | 3-5 years | Straight-line |
| Leasehold improvements | Lease term or useful life (shorter) | Straight-line |
When to Use Accelerated Depreciation
| Scenario | Recommended Method | Why |
|---|---|---|
| High current-year income | DDB | Maximises deduction now, reducing current tax bill |
| Asset loses value fast (tech) | DDB or SYD | Matches the actual decline in usefulness |
| Steady, predictable use | Straight-line | Simplest to calculate and explain, matches even usage |
| HMRC / IRS compliance | Depends on jurisdiction | Tax authorities may require specific methods for certain asset classes |
Book Value vs Market Value
Depreciation reduces the book value (accounting value) of an asset, but the market value (what you could sell it for) may be different. A company car might have a book value of £5,000 after 4 years of depreciation but a market value of £8,000. The book value is used for financial statements and tax calculations, while market value matters for insurance and resale.
For evaluating the return on your asset investment, the ROI calculator shows return on investment. For understanding your overall business cost structure, the break-even calculator includes fixed costs like depreciation. All calculations run in your browser.
Frequently Asked Questions
What is the difference between the four depreciation methods?
Straight-line spreads the cost evenly across all years. Declining balance applies a fixed rate to the remaining book value each year. Double declining uses twice the straight-line rate for faster early depreciation. Sum-of-years digits weights depreciation more heavily in earlier years using a fraction based on remaining useful life.
What is salvage value?
Salvage value (or residual value) is the estimated worth of the asset at the end of its useful life. Only the difference between the cost and salvage value is depreciated. If you expect to sell equipment for 5,000 after using it, that 5,000 is the salvage value.
Which depreciation method should I use?
Straight-line is the simplest and most common for financial reporting. Accelerated methods (declining balance, double declining, sum-of-years) front-load more depreciation expense into earlier years, which can provide tax benefits. Check your local tax regulations for which methods are acceptable.
How is double declining balance calculated?
The depreciation rate is twice the straight-line rate (2 divided by useful life). This rate is applied to the current book value each year, not the original cost. The depreciation stops when the book value reaches the salvage value.
Can book value go below salvage value?
No. In all methods, depreciation stops once the book value reaches the salvage value. The calculator automatically caps depreciation in any year where it would push the book value below salvage.
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