Depreciation Calculator — SL, DDB & SYD Methods
Calculate how much an asset depreciates each year. Enter the original cost, salvage value, useful life, and choose from straight-line, double-declining balance, or sum of years' digits to get the first-year expense and a declining book-value chart.
years
Depreciation method
Depreciation expense recognised in the first year
- 1
Depreciable amount
10,000 − 1,000 = 9,000 - 2
Year 1 depreciation
9,000 ÷ 5 = 1,800Straight-line: equal charge every year.
How does this calculator work?
Depreciation spreads an asset's cost over its useful life. Straight-line: constant annual charge = (Cost − Salvage) ÷ n. Double-declining balance: early-heavy charges using 2/n × book value. Sum of years' digits: declining fraction of the depreciable amount each year. Book value always stops at the salvage floor and equals salvage at end of life.
Formula
How this is calculated
Depreciation allocates the cost of a long-lived asset over its useful life, matching the expense to the periods the asset helps generate revenue. The depreciable amount is always cost minus salvage value — the floor below which the book value cannot fall.
Straight-line (SL) spreads the depreciable amount equally over all years, producing a constant annual charge. It is the most common method and is the default under IFRS (IAS 16) and US GAAP (ASC 360) for most tangible assets. Double-declining balance (DDB) is an accelerated method: in each year the book value is multiplied by twice the straight-line rate (2/n), front-loading expenses. Because the rate is applied to the declining balance, the charge automatically falls each year; the asset is never depreciated below salvage value. Sum of years' digits (SYD) is also accelerated but gentler than DDB: the fraction applied each year is (remaining life) ÷ SYD, where SYD = 1 + 2 + … + n = n(n+1)/2. Larger fractions appear early, tapering to small ones near the end.
The calculator assumes a full first year of depreciation (no half-year or mid-quarter convention) and fixed salvage and useful-life estimates. Many tax authorities specify different rules — MACRS in the US, capital allowances in the UK — that override these methods; consult an accountant for tax-compliant treatment.
Frequently asked questions
It depends on the asset and the purpose. Straight-line suits assets that wear evenly over time — buildings, furniture. Double-declining balance suits assets that lose value quickly early in life — technology, vehicles. Sum of years' digits is a middle ground. Tax rules often mandate specific methods; consult an accountant for the optimal choice.
Salvage (residual) value is the estimated amount the asset will be worth at the end of its useful life. The asset is never depreciated below this floor. If you expect the asset to be worthless or scrapped, enter 0.
Annual depreciation = (Cost − Salvage value) ÷ Useful life in years. For example, a machine costing £10 000 with a £1 000 salvage value over 5 years depreciates at (10 000 − 1 000) ÷ 5 = £1 800 per year, with a book value of £8 200 after year 1.
Also known as
TG we-Calculate Editorial Team. (2026). Depreciation Calculator — SL, DDB & SYD Methods [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/depreciation-calculator
TG we-Calculate Editorial Team. "Depreciation Calculator — SL, DDB & SYD Methods." TG we-Calculate. 2026. https://we-calculate.com/calculator/depreciation-calculator.
TG we-Calculate Editorial Team, "Depreciation Calculator — SL, DDB & SYD Methods," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/depreciation-calculator
@misc{wecalculate_depreciation_calculator, title = {Depreciation Calculator — SL, DDB & SYD Methods}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/depreciation-calculator}}, year = {2026}, note = {TG we-Calculate} }
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