Depreciation Calculator
Enter what an asset cost, what it will be worth at the end of its useful life and how many years that life lasts. The calculator lays out each year's depreciation and the book value left at year end by three methods side by side: straight-line, double declining balance and sum-of-the-years' digits.
| Year | SL Depr. | SL Book | DDB Depr. | DDB Book | SOYD Depr. | SOYD Book |
|---|---|---|---|---|---|---|
| 1 | $9,000.00 | $41,000.00 | $20,000.00 | $30,000.00 | $15,000.00 | $35,000.00 |
| 2 | $9,000.00 | $32,000.00 | $12,000.00 | $18,000.00 | $12,000.00 | $23,000.00 |
| 3 | $9,000.00 | $23,000.00 | $7,200.00 | $10,800.00 | $9,000.00 | $14,000.00 |
| 4 | $9,000.00 | $14,000.00 | $4,320.00 | $6,480.00 | $6,000.00 | $8,000.00 |
| 5 | $9,000.00 | $5,000.00 | $1,480.00 | $5,000.00 | $3,000.00 | $5,000.00 |
How to use the Depreciation Calculator
- Enter your numbers in the Depreciation Calculator above.
- The result updates as you type, so there is no button to press.
- Change any value to see how the result moves.
The depreciation methods
Straight-line: D = (Cost − Salvage) / Life Double declining: D = Book value at the start of the year × 2 / Life Sum-of-the-years' digits: D = (Cost − Salvage) × (Life − Year + 1) / (Life × (Life + 1) / 2)
Straight-line takes the same amount every year. Double declining balance takes a fixed share of what is left, so the early years carry the most, and it never takes book value below salvage. Sum-of-the-years' digits also front-loads, by a shrinking fraction of the depreciable amount: for 5 years the fractions are 5/15, 4/15, 3/15, 2/15 and 1/15. Each year is rounded to the cent. For straight-line and sum-of-the-years' digits, the last year takes what is left, so book value ends exactly at salvage. Double declining balance here does not switch to straight-line, so with a long life its book value can end above salvage, and the calculator notes it under the table. It takes costs from 0.01 to 1 trillion and lives of 1 to 50 whole years.
Worked example
The fields start with a $50,000 machine, $5,000 salvage value and a 5-year life. Straight-line takes (50,000 − 5,000) / 5 = $9,000 a year. Double declining takes 40% of book value: $20,000, $12,000, $7,200 and $4,320, then $1,480 in year 5, which stops at the $5,000 salvage value. Sum-of-the-years' digits takes 5/15, 4/15, 3/15, 2/15 and 1/15 of $45,000: $15,000, $12,000, $9,000, $6,000 and $3,000. With a 10-year life instead, straight-line is $4,500 a year and double declining takes $10,000 in year 1 and $8,000 in year 2, but ends at a book value of $5,368.71, above salvage.
Frequently asked questions
Which method should I use for taxes?
For a US tax return, IRS Publication 946 (for 2025 returns) says you must use MACRS, the Modified Accelerated Cost Recovery System, to depreciate most property. MACRS sets its own recovery periods and tables, which this calculator does not apply. Use the publication or a tax professional for the figure on your return, and this calculator for book depreciation and comparisons.
What is salvage value?
Your estimate of what the asset will be worth at the end of its useful life. Straight-line and sum-of-the-years' digits spread cost minus salvage over the life. Double declining balance works from the full book value and only stops when the next year would take it below salvage.
Why use accelerated depreciation?
Double declining balance and sum-of-the-years' digits put more of the cost into the early years. They fit an asset you expect to lose most of its value early. In the table, both give a larger year 1 figure than straight-line.