Double Declining Balance Depreciation Calculator

What the double declining balance calculator does

The double declining balance depreciation calculator shows how much value a business asset loses each year under the DDB method, a widely used accelerated depreciation technique. DDB records a large expense in the first year and progressively smaller amounts after that. Enter the asset cost, the salvage value you expect at the end of its life, and the number of years you plan to use it, and the calculator returns the depreciation rate, the first-year write-off, and the remaining book value.

Many assets are most useful, and lose value fastest, in their early years. A double declining balance schedule matches the expense to that period.

How the double declining balance method works

The method uses double the straight-line rate. The straight-line rate is one divided by the useful life, so an asset with a ten-year life has a straight-line rate of 10% per year. DDB doubles that to 20% and applies it to the asset's book value, meaning its cost minus all depreciation taken so far.

Because the rate is applied to a shrinking balance, the expense falls each year even though the percentage stays the same. In the first year the full cost is exposed to the rate, producing the largest deduction. In the second year the smaller remaining book value is multiplied by the same rate, and so on, so the expense starts high and flattens over time.

Unlike the straight-line approach, DDB does not subtract salvage value before applying the rate. Salvage value is a floor: the asset keeps depreciating until its book value reaches the salvage figure, and then depreciation stops. In practice the final year's expense is often adjusted so that book value lands exactly on the salvage value.

The formula

• Depreciation rate = 2 ÷ useful life, written as a percentage.
• First-year depreciation = asset cost × depreciation rate.
• Book value after year one = asset cost − first-year depreciation.

Each later year repeats the second step from the reduced book value. The calculator reports the rate, the first-year expense, and the book value at the end of year one, and the chart plots the full schedule across the asset's life.

Reading your results

A higher depreciation rate means faster expensing. The first-year depreciation is usually the figure that matters most for planning, since it is the largest single deduction and has the biggest effect on early profit and tax. The book value after year one is what remains on the balance sheet and the starting point for the following year.

The chart shows every year's expense side by side: tall bars at the start, shrinking toward the end. Set against a flat straight-line schedule, it shows what "accelerated" means for your numbers.

When to choose accelerated depreciation

DDB suits assets that lose value quickly or become obsolete fast, such as computers, software-heavy equipment, vehicles, and consumer technology. For these, a front-loaded expense schedule is closer to how the asset actually loses value.

Larger deductions in the early years also reduce taxable profit sooner, which can free up cash just after a significant purchase. The total written off is the same under any method, so the gain is in timing only.

On the other hand, DDB reports lower profits in the early years, which some businesses want to avoid, and because the calculation changes each year it takes more effort to maintain than a straight-line schedule.

Comparing DDB with other methods

Straight-line depreciation spreads the depreciable amount evenly and produces the same expense every year. The sum-of-the-years'-digits method is also accelerated but tapers more gently. DDB gives the steepest early write-off of the common methods.

If you run the same asset through each method, the total depreciation over its life is identical but the year-by-year pattern differs, and that pattern shapes reported profit, tax timing, and the value on the balance sheet at any given moment.

Using the results

Depreciation rules vary by country and by type of asset, and local tax law may prescribe methods, rates, or conventions that differ from a textbook DDB schedule. Use the calculator to see the shape and scale of accelerated depreciation, then confirm the treatment that applies to you with an accountant or the relevant tax authority.

Shortening the useful life sharply increases the early expense, and changing the salvage value moves the point where the schedule flattens out.

This article is general information only and is not accounting or tax advice.

About This Double Declining Balance Depreciation Calculator

Use this double declining balance depreciation calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.