Straight Line Depreciation Calculator
Calculate annual depreciation, book value and a full asset schedule instantly. Fully usable on mobile.
How to Use the Depreciation Calculator
From an asset cost to a full year by year schedule in seconds. Fully usable on mobile.
Every calculation runs inside your own browser. No account, no tracking, nothing ever uploaded.
Straight Line Depreciation Calculator, Free and Online
A straight line depreciation calculator spreads an asset's depreciable cost, its purchase price minus salvage value, evenly across its useful life, so every year carries the same expense. This one also includes Double Declining Balance, Sum of Years Digits, and Units of Production in Pro mode, plus a full schedule, a chart, and export to CSV, JSON, HTML or PDF.
Straight line is the default depreciation method most businesses use for their own books, and it is exactly what most accounting classes teach first, because it is the easiest to compute and the easiest to explain to someone who is not an accountant. Enter the asset cost, the estimated salvage value, and the useful life in years, and this straight line depreciation calculator gives you the annual depreciation, the depreciation rate, and a full year by year schedule showing accumulated depreciation and book value. Pro mode adds three more methods used when a business wants to accelerate deductions or match expense to actual usage, a side by side comparison of all four, a book value chart, and export options for handing a schedule to a client or filing it with your own records.
Cost minus salvage value is called the depreciable cost, the only portion of the asset's price that ever gets expensed. Divide it evenly across the useful life and you have the straight line answer.
1Simple vs Pro, What Each Mode Includes
| Feature | Simple Mode | Pro Mode (Free) |
|---|---|---|
| Straight line method, full schedule | Included | Included |
| Double Declining Balance, Sum of Years Digits, Units of Production | Not included | Included |
| Method comparison table | Not included | Included |
| Book value chart | Not included | Included |
| Custom currency and start year | Not included | Included |
| Copy and CSV export | Included | Included |
| JSON, HTML and Print/PDF export | Not included | Included |
2The Four Depreciation Methods, Quick Reference
The mistake that trips up the most people using an accelerated method is forgetting that book value can never fall below salvage value. Double Declining Balance applies a fixed rate to whatever the asset is currently worth, which means left alone it would approach zero but never actually reach it. The correct handling, and what this calculator does automatically, is to switch over to straight line partway through the schedule once that method would depreciate the asset faster than DDB would on its own, guaranteeing the asset lands exactly on its salvage value in the final year rather than drifting past it or falling short.
3Where Formal Depreciation Accounting Actually Came From
Depreciation as a required, standardized accounting practice is younger than most people assume. For much of the 19th century, many companies simply expensed the full cost of a machine or a building in the year they bought it, or ignored the asset's declining value entirely until it was finally sold or scrapped, either of which produced a profit figure that had little to do with economic reality. According to a study published in the Accounting Historians Journal, the American railroads forced the issue. In June 1907, the Interstate Commerce Commission ordered railroads to abandon the older betterment accounting they had been using and adopt formal depreciation accounting for their equipment instead. The railroads protested loudly, arguing they were already accounting for wear and tear under the old system, but the ICC held that matching the cost of long lived equipment to the revenue it helped generate, year by year, gave regulators a far more reliable picture of a railroad's actual earnings. That fight over a handful of railroad ledgers in the early 1900s is a direct ancestor of the straight line method taught in every introductory accounting course today.
| Question | Quick Answer |
|---|---|
| Who forced railroads to adopt depreciation accounting? | The Interstate Commerce Commission |
| When did this happen? | June 1907, with debate continuing to 1913 |
| What system were railroads using before? | Betterment accounting |
| Why did the ICC push the change? | To match equipment cost to the revenue it generated, for more reliable reported income |
Every calculation runs inside your own browser using JavaScript, nothing is uploaded or sent to a server, and no account or signup is required.
4Frequently Asked Questions
Grounded in the Accounting Historians Journal's own peer-reviewed account of the 1907 to 1913 railroad depreciation debate, not a generic history claim with no source. The full article is available via the American Accounting Association. For related tools on this site, see the Freelance Tax Calculator and the full SmallStudyTools.com tool library.
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