Double Declining Balance Depreciation Calculator
Calculate annual depreciation using the double declining balance method. Find the depreciation amount, accumulated depreciation, and book value for any year of an asset's useful life.
How to use this tool
- Enter asset cost (original), salvage value, useful life and year to calculate in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your depreciation this year and the full breakdown beneath it.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
The Double Declining Balance (DDB) rate is:
Rate = 2 / Useful Life
Each year's depreciation is:
Depreciation = Book Value × Rate
Depreciation stops when Book Value reaches the Salvage Value: Max Dep = max(Book Value − Salvage, 0)
How it works
The double declining balance method is an accelerated depreciation technique that applies twice the straight-line depreciation rate to the asset's remaining book value each year. Because depreciation is calculated on a declining balance rather than original cost, the deduction is largest in the early years and decreases over time. The book value never falls below the estimated salvage value.
Worked example
Year 1 Depreciation on a $10,000 Asset
- Asset cost = $10,000; salvage value = $1,000; useful life = 5 years.
- DDB rate = 2 / 5 = 0.40 (40%).
- Year 1 book value starts at $10,000. Max depreciable amount = $10,000 - $1,000 = $9,000.
- Year 1 depreciation = $10,000 × 40% = $4,000 (which is below the $9,000 cap).
- Ending book value = $10,000 - $4,000 = $6,000.
Year 1 depreciation is $4,000.00; book value at year end is $6,000.00.
Common mistakes to avoid
- Forgetting that depreciation stops when book value reaches the salvage value — continuing to apply the DDB rate past that floor overstates accumulated depreciation.
- Using straight-line useful life in the denominator but treating it as the DDB rate directly; the rate is 2 / Useful Life, not 1 / Useful Life.
- Failing to switch to straight-line in the final years when SL would yield a higher deduction, which is standard DDB practice and often required under GAAP.
Key terms
- What is double declining balance depreciation?
- An accelerated depreciation method that deducts twice the straight-line rate applied to the asset's remaining book value each period.
- What is salvage value?
- The estimated residual value of an asset at the end of its useful life; depreciation stops when the book value reaches this amount.
- How does DDB differ from straight-line depreciation?
- Straight-line spreads cost evenly over the asset's life, while DDB front-loads larger deductions in early years, reducing taxable income sooner.
- What is book value?
- The net value of an asset on the balance sheet: original cost minus accumulated depreciation.
Frequently asked questions
- When should I switch from DDB to straight-line depreciation?
- Switch to straight-line in the year straight-line depreciation on the remaining book value exceeds the DDB amount. This avoids under-depreciating the asset before it reaches salvage value.
- Can the book value go below salvage value using DDB?
- No. Depreciation stops once the book value equals the salvage value, even if the DDB formula would produce a larger deduction.
- Is double declining balance the same as 200% declining balance?
- Yes. DDB uses a rate of 2 / Useful Life, which is twice the straight-line rate, equivalent to 200% of the straight-line method.