Straight Line Depreciation Calculator
Enter an asset’s cost, salvage value and useful life to see yearly depreciation and book value. The default example expenses $9,000.00 a year.
How the straight line depreciation calculator works
Straight line depreciation spreads the cost of an asset evenly over its useful life. You subtract the salvage value, which is what you expect the asset to be worth at the end, and divide the remainder by the number of years. The same expense is recorded each year, which makes it the simplest and most widely used depreciation method.
Enter the asset cost, the salvage value, the useful life in years and the number of years the asset has been in service. The calculator returns the yearly and monthly expense, the straight line rate, the accumulated depreciation and the remaining book value at that point. If you enter more years in service than the useful life, the tool stops at the end of the life, since an asset cannot be depreciated below its salvage value.
The formulas
Example: Equipment costs $50,000, has a $5,000 salvage value and a 5-year life. The depreciable base is $45,000.00, which gives $9,000.00 a year, or $750.00 a month, a rate of 20% of the base each year. After 3 years, accumulated depreciation is $27,000.00 and book value is $23,000.00. These are illustration numbers only.
Book versus tax depreciation
This calculator follows the accounting method used in a company’s own books. Tax depreciation can follow different rules, recovery periods and conventions. IRS Publication 946, How To Depreciate Property (2025 edition), explains how depreciation works for US tax purposes. Check it or ask a tax professional before using any figure on a return.
This tool is for general information, not tax or accounting advice. To compare other methods or run a different schedule, use our depreciation calculator, or read how to calculate depreciation for the full walkthrough.
The salvage value cannot be higher than the cost, or the depreciable base is negative and the calculator returns n/a. If an asset is expected to have no resale value, enter zero for salvage. Enter the useful life in years, even if the asset is used part-time, to match the schedule you plan to use.
When straight line fits
Straight line works best when an asset delivers about the same benefit each year, such as office furniture, a building improvement or a vehicle used steadily. If an asset loses most of its value early, as many technology items do, a front-loaded method may describe it better. A partial first year is common in practice: if an asset enters service mid-year, you would normally record only the months in use. You can approximate that by entering the years in service as a decimal.
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Frequently asked questions
What is straight line depreciation?
It is a method that expenses the same amount each year: cost minus salvage value, divided by useful life.
How do I calculate it in Excel?
Use =SLN(cost, salvage, life). For the default example it returns the same $9,000.00 a year shown above.
What is salvage value?
It is the estimated amount the asset will be worth at the end of its useful life. Depreciation stops when book value reaches it.
Does this match tax depreciation?
Not necessarily. Tax rules can use other methods and recovery periods. See IRS Publication 946 or a tax professional.
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