Depreciation Calculator – Straight Line, Declining Balance & Sum-of-Years

What Is Depreciation?

Depreciation is the systematic allocation of a fixed asset's cost over its useful life. Rather than recording the entire purchase price as an expense in the year of acquisition, businesses spread the cost over the years during which the asset generates economic benefit. This practice follows the matching principle of Generally Accepted Accounting Principles (GAAP), which requires expenses to be recognized in the same period as the revenues they help generate.

Depreciation affects both the income statement (as an operating expense that reduces net income) and the balance sheet (as accumulated depreciation that reduces the asset's carrying value). It also has significant implications for tax reporting, as the IRS allows businesses to deduct depreciation as a business expense.

Key Terms and Definitions

Asset Cost (Original Cost)

The total amount paid to acquire the asset, including purchase price, shipping, installation, and any costs necessary to bring the asset into service.

Salvage Value (Residual Value)

The estimated value of the asset at the end of its useful life. Some assets have zero salvage value; others retain significant residual worth. Salvage value is subtracted from the asset cost to determine the total depreciable base.

Useful Life

The expected number of years an asset will remain productive and in use. The IRS publishes guidelines on useful life for various asset classes under the Modified Accelerated Cost Recovery System (MACRS) — IRS Publication 946.

Book Value

The net value of an asset recorded on the balance sheet, calculated as Asset Cost minus Accumulated Depreciation.

Accumulated Depreciation

The total depreciation recorded against an asset since it was placed in service. It is a contra-asset account that reduces the gross asset value on the balance sheet.

Depreciation Factor

Used in the Declining Balance method. A factor of 1.5 represents 150% declining balance; a factor of 2 represents 200% (Double Declining Balance). Higher factors result in more aggressive early-year depreciation.

How to Use This Depreciation Calculator

Follow these steps to calculate your asset's depreciation schedule:

1. Select a Depreciation Method — Choose Straight Line, Declining Balance, or Sum-of-Years' Digits from the dropdown menu.
2. Enter Asset Cost — Input the original purchase price (cost basis) of the asset in dollars.
3. Enter Salvage Value — Input the estimated residual value of the asset at the end of its useful life.
4. Enter Useful Life — Input the number of years over which the asset will be depreciated.
5. Enter Depreciation Factor (Declining Balance only) — Enter the factor applied to the straight-line rate. A factor of 2 = double-declining balance (200% DB).
6. Click Calculate — The calculator will generate a full depreciation schedule, pie chart, and bar chart instantly.

Depreciation Methods Explained

1. Straight-Line Depreciation (SL)

The straight-line method is the simplest and most commonly used depreciation method. It allocates an equal amount of depreciation expense each year over the asset's useful life.

Formula:

Annual Depreciation = (Asset Cost − Salvage Value) ÷ Useful Life

Example: An asset costs \$11,000 with a \$1,000 salvage value and a 5-year useful life.
Annual Depreciation = (\$11,000 − \$1,000) ÷ 5 = \$2,000 per year

Straight-line depreciation is required or preferred under many accounting standards and is widely used for buildings, furniture, and equipment with consistent usage patterns.

2. Declining Balance Depreciation (DB)

The declining balance method is an accelerated depreciation method that applies a fixed percentage rate to the asset's remaining book value each year. Because the book value decreases every year, so does the depreciation amount — but the rate stays constant.

Formula:

Annual Depreciation Rate = Depreciation Factor ÷ Useful Life
Depreciation Amount = Beginning Book Value × Annual Rate

The most common version is the Double Declining Balance (DDB) method, which uses a factor of 2. It is widely used for tax purposes because it front-loads depreciation deductions, reducing taxable income in the early years of an asset's life.

Note: The book value cannot fall below the asset's salvage value. Once book value reaches salvage value, no further depreciation is recorded.

3. Sum-of-Years' Digits Depreciation (SYD)

The Sum-of-Years' Digits method is another accelerated depreciation method. It results in higher depreciation in the earlier years and lower depreciation toward the end of the asset's useful life.

Formula:

Sum of Years' Digits (S) = n × (n + 1) ÷ 2, where n = useful life in years
Depreciation Fraction (Year t) = (n − t + 1) ÷ S
Depreciation Amount (Year t) = (Asset Cost − Salvage Value) × Depreciation Fraction
Annual Depreciation = (Remaining Life ÷ Sum of Years) × (Asset Cost − Salvage Value)

Example: For a 5-year asset, S = 5+4+3+2+1 = 15.
Year 1 fraction = 5/15 = 33.33%
Year 2 fraction = 4/15 = 26.67%
Year 5 fraction = 1/15 = 6.67%

Depreciation Schedule Table Explained

The depreciation schedule table generated by this calculator contains the following columns:

• Year — The year number within the asset's useful life.
• Beginning Book Value — The asset's net book value at the start of the year (equals the prior year's ending book value).
• Depreciation Percent — The percentage of the beginning book value (or depreciable base) depreciated in that year.
• Depreciation Amount — The dollar amount of depreciation expense recognized in that year.
• Accumulated Depreciation — The total depreciation recorded from the start of the asset's life through the end of that year.
• Ending Book Value — The asset's net book value at the end of the year (Beginning Book Value minus Depreciation Amount). This value is reported on the balance sheet.

FAQ

What Is Straight-line Depreciation?

Straight-line depreciation spreads an asset's depreciable cost evenly over its useful life. Formula: Annual Depreciation = (Asset Cost – Salvage Value) ÷ Useful Life. It is the simplest and most commonly used depreciation method for financial reporting.

What Is Declining Balance Depreciation?

The declining balance method applies a constant depreciation rate to the asset's remaining book value each year, resulting in higher depreciation charges in earlier years. The double-declining balance method uses a factor of 2 and is widely used for tax depreciation purposes.

What Is Sum-of-years' Digits Depreciation?

Sum-of-Years' Digits (SYD) is an accelerated depreciation method. Each year's depreciation fraction = remaining useful life ÷ sum of all years' digits. For a 5-year asset, the sum of digits = 1+2+3+4+5 = 15. Year 1 depreciation fraction = 5/15.

What Is Salvage Value?

Salvage value (also called residual value or scrap value) is the estimated value of a fixed asset at the end of its useful life. The depreciable base of an asset equals its original cost minus its salvage value.

What Is Book Value?

Book value is the net value of an asset recorded on the balance sheet. It equals the original cost of the asset minus accumulated depreciation to date. Book value decreases each year as depreciation is recorded.

Which Depreciation Method Should I Use?

The best method depends on your accounting needs and tax situation. Straight-line is simplest and most used for financial reporting. Declining balance and Sum-of-Years' Digits are accelerated methods that reduce taxable income more in early years. Consult a qualified accountant or tax professional for your specific situation.

Can an asset be depreciated below its salvage value?

No. Under all standard depreciation methods, an asset's book value cannot be reduced below its estimated salvage value. Depreciation stops once the book value equals the salvage value.

What assets can be depreciated?

Tangible business assets with a useful life of more than one year can be depreciated. Common examples include machinery, vehicles, computers, office furniture, buildings, and manufacturing equipment. Land is not depreciable. For a full list of asset classes and recovery periods, see IRS Publication 946.

What is the depreciable base of an asset?

The depreciable base (also called the depreciable cost) is the total amount that will be depreciated over the asset's useful life. It equals: Asset Cost − Salvage Value.

What is double-declining balance depreciation?

Double-declining balance (DDB) is a specific form of declining balance depreciation that uses a factor of 2. The annual depreciation rate = 2 ÷ Useful Life. For example, for a 5-year asset, the DDB rate = 2 ÷ 5 = 40% per year applied to the remaining book value.

Is depreciation a cash expense?

No. Depreciation is a non-cash expense. It reduces net income on the income statement but does not involve any actual cash outflow. On the cash flow statement, depreciation is added back to net income under operating activities because it reduced income without using cash.

References

• IRS Publication 946 – How to Depreciate Property (Internal Revenue Service) — Official IRS guide covering MACRS, depreciation methods, useful life tables, and Section 179 deduction rules.
• Financial Accounting Standards Board (FASB) – Accounting Standards — Official GAAP standards governing how businesses report depreciation in financial statements.
• U.S. Small Business Administration (SBA) – Managing Business Finances — Guidance for small business owners on financial management, including asset tracking.
• U.S. Securities and Exchange Commission (SEC) – Depreciation Overview — SEC explanation of how depreciation affects public company financial disclosures.
• U.S. Government Accountability Office (GAO) – Federal Accounting Standards — GAO report on asset management and depreciation standards in federal accounting.