2026-07-31 8 min

Depreciation Calculator

Calculate depreciation with straight-line, double declining balance, and sum-of-years-digits methods. See annual depreciation and book value for every year of an asset life.

Calculator

Unit System

Asset Cost Help

Initial cost of the asset including installation

Salvage Value Help

Expected value of the asset at the end of its useful life

Useful Life(yr) Help

Expected service life of the asset in years

Year to Evaluate(yr) Help

Year for which the depreciation and book value are reported

Results update live as you type

Results

Normal

Straight-Line Depreciation

4500.00$/yr

Depreciable base divided by useful life

Declining Balance Year 1

10000.00$/yr

Double declining balance depreciation in the first year

SYD Depreciation (Selected Year)

4500.00$/yr

Sum-of-years-digits depreciation in the selected year

Book Value after Selected Year

11500.00$

Asset cost minus straight-line depreciation through the selected year

Declining Balance Book Value

5400.00$

Book value under double declining balance, floored at salvage value

Total Depreciation over Life

22500.00$

Total straight-line depreciation, equal to the depreciable base

Visualizations

Depreciation by Method (Year 1)

4,500$Straight Line

10,000$Declining Balance

7,500$Sum-of-Years

Formula

Straight-line spreads the depreciable base evenly over the life. Double declining balance applies twice the straight-line rate to the remaining book value. Sum-of-years-digits weights each year by the remaining life over the sum of all year digits.

SL = (Cost − Salvage) / Life; DB₁ = Cost × 2 / Life; SYDₜ = Base × (Life − t + 1) / (Life × (Life + 1) / 2)

Alternative Form

BookValueₜ = Cost − AccumulatedDepreciationₜ

Variables

Symbol	Name	Unit	Description
Cost	Asset cost	$	Initial cost of the asset
Salvage	Salvage value	$	Value remaining at the end of the useful life
Life	Useful life	yr	Depreciation period in years
t	Year being evaluated	yr	The year for which depreciation is reported

Explanation

Depreciation allocates an asset cost over its useful life for accounting, tax, and cost analysis. Straight-line gives a constant annual charge; declining balance front-loads depreciation; SYD falls between the two with a declining annual amount.

Derivation

The depreciable base is Cost minus Salvage. Straight-line divides the base by Life. Double declining balance applies 2/Life to the declining book value each year. SYD denominator is the sum 1+2+...+Life = Life(Life+1)/2, and year t takes a share of the base proportional to Life−t+1.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Compute the depreciable base.

Base = Cost − Salvage

Result: Depreciable Base: $22500.00

Step 2

Calculate straight-line depreciation per year.

SL = Base / Life

Result: Straight-Line: $4500.00 /yr

Step 3

Calculate double declining balance for year 1.

DB₁ = Cost × 2 / Life

Result: Declining Balance: $10000.00

Step 4

Calculate sum-of-years-digits depreciation for the selected year.

SYDₜ = Base × (Life − t + 1) / Denom

Result: SYD (Yr 3): $4500.00

Step 5

Calculate book value after the selected year.

Book = Cost − SL × t

Result: Book Value: $11500.00

Final Answer

4500.00

Worked Examples

See how the calculator works with different scenarios.

Scenario

A $25,000 machine with $2,500 salvage value is depreciated over 5 years. Evaluate year 3.

Inputs

Asset Cost:$25,000

Salvage:$2,500

Life:5 yr

Year:3

Calculation

Base = 25,000 − 2,500 = $22,500 SL = 22,500 / 5 = $4,500/yr DB₁ = 25,000 × 40% = $10,000 SYD Denom = 5 × 6 / 2 = 15 SYD₁ = 22,500 × 5 / 15 = $7,500 SYD₃ = 22,500 × 3 / 15 = $4,500 Book after yr 3 = 25,000 − 4,500 × 3 = $11,500 DB book after yr 3 = 25,000 × 0.6³ = $5,400

Result

SL: $4,500/yr, DB Year 1: $10,000, SYD Year 3: $4,500, Book Value: $11,500

Interpretation

Declining balance writes off 40% of cost in year 1, nearly matching the total straight-line deduction of the whole 3-year period. Choose the method that matches how the asset actually loses value.

Understanding Your Result

Your Result: Straight-Line Depreciation: 4500.00 $/yr

Typical range: Industrial machinery commonly uses 5-15 year lives. Straight-line is standard for financial reporting; declining balance or MACRS is common for tax; SYD is used where assets lose value fastest at the start.

What This Means

Depreciation converts the cost of a long-lived asset into annual expense charges. Straight-line charges evenly, double declining balance charges most early, and sum-of-years-digits declines steadily each year.

Why It Matters

Depreciation affects taxes, reported profit, book value, and cost allocation. The chosen method changes when costs hit the income statement, which matters for budgeting and for hourly machine rates.

Professional Interpretation

Accountants keep one depreciation method for reporting and may use an accelerated method for tax. Engineers use depreciation to build machine-hour rates and to track real asset values for replacement decisions.

Recommendations

•Match the method to how the asset actually loses value
•Use the same convention and life for assets in the same class
•Check tax rules before choosing an accelerated method
•Track book value against real resale value for replacement decisions
•Document the method and assumptions in asset records

Educational Content

Introduction

Depreciation is the systematic allocation of an asset cost over its useful life. It reflects the economic reality that machinery and equipment wear out, become obsolete, and lose value as they are used.

Concept Explanation

All methods start from the depreciable base (cost minus salvage). Straight-line splits it evenly. Double declining balance applies twice the straight-line rate to the declining book value. Sum-of-years-digits applies a decreasing fraction of the base each year.

Applications

▸Financial statement reporting

▸Tax deduction planning

▸Machine-hour rate development

▸Book value tracking for replacement analysis

▸Asset portfolio valuation

▸Budgeting for capital renewal

Benefits

•Matches expense to the period the asset is used
•Front-loads expense where value loss is front-loaded
•Provides a defensible basis for cost allocation
•Simple to compute and audit
•Standard across industries for comparability

Limitations

•Does not reflect true market value
•Assumes a predictable loss pattern
•Ignores inflation and obsolescence
•Method choice is partly arbitrary

Best Practices

•Set lives from actual industry and company experience
•Review asset lives annually
•Keep method consistent within asset classes
•Reconcile book value with physical condition
•Use separate books for tax and financial reporting

Common Misconceptions

Myth: Depreciation is a cash expense.

Truth: Depreciation is a non-cash allocation of a past purchase; the cash left when the asset was bought, not as depreciation is recorded.

Myth: Book value equals market value.

Truth: Book value is an accounting construct. Resale value can be higher or lower depending on the market.

Myth: Double declining balance is always better for taxes.

Truth: Accelerated methods help in some tax regimes and years but can be neutral or unfavorable in others; check current tax rules.

Practical Tips

•Use the same life across similar assets so comparisons are valid
•Floor book value at salvage value, never below
•Review half-year and mid-quarter conventions for tax depreciation
•Combine the schedule with replacement analysis for aging assets
•Document method choice in the fixed-asset register

Common Mistakes

Depreciating below salvage value

Floor book value at the salvage value; depreciation stops once the base is fully recovered.

Using an arbitrary useful life

Base lives on industry tables, warranty periods, and actual equipment replacement history.

Mixing methods within one asset class

Pick one method per class and keep it consistent for comparability.

Treating book value as resale value

Use market data for resale decisions and book value only for accounting.

Assumptions

This calculator makes the following assumptions to provide estimates:

Constant Depreciable Base: The base is cost minus salvage with no mid-life additions or impairments.

Full-Year Convention: Depreciation starts at the beginning of year 1; no mid-year or half-year conventions are applied.

Positive Salvage Bound: Declining balance book value is floored at the salvage value.

Integer Life for Schedules: Year-by-year schedules are built for the rounded useful life.

Limitations

Be aware of these limitations when using this calculator:

No Tax Conventions: MACRS, half-year, and mid-quarter conventions are not modeled; consult tax rules separately.

No Partial Year Handling: Assets acquired mid-year are treated as if owned for the full first year.

Accounting Only: Depreciation is not a cash flow; use NPV and cash-flow tools for investment decisions.

Frequently Asked Questions

Answers to common questions about this calculator.

What does the depreciation calculator compute?

It computes annual depreciation under straight-line, double declining balance, and sum-of-years-digits methods, plus book values and full year-by-year schedules.

What is the depreciable base?

The asset cost minus the salvage value. It is the total amount to be depreciated over the useful life.

What is straight-line depreciation?

An equal annual charge: (cost − salvage) ÷ useful life. It is the most common method for financial reporting.

What is double declining balance?

An accelerated method applying twice the straight-line rate to the remaining book value each year.

What is sum-of-years-digits?

A method where each year charges a share of the base proportional to the remaining life, giving steadily declining amounts.

Which depreciation method should I use?

Straight-line for simple financial reporting, an accelerated method for assets that lose value quickly, and tax rules if the purpose is tax.

What is book value?

The asset cost minus accumulated depreciation. It is the accounting value remaining on the books.

Why is the declining balance floored at salvage?

To avoid depreciating below the salvage value, since the asset is still worth that amount.

Does this calculator apply tax conventions like MACRS?

No. It models three standard accounting methods without half-year or mid-quarter conventions.

What is a typical useful life for machinery?

5-15 years depending on type; the IRS publishes class lives, and industry associations publish typical equipment lives.

Can I see depreciation for every year?

Yes, the diagram plots book value for the full life, and the results report the selected year.

Is depreciation a cash expense?

No. It is a non-cash allocation of an earlier purchase, used for accounting and cost allocation.

Is this calculator free?

Yes, it runs entirely in your browser with no registration and no data collection.

What if salvage value is zero?

The full cost becomes the depreciable base, and the asset is depreciated to zero.

What happens if I evaluate a year beyond the useful life?

SYD depreciation shows "---" because no depreciation occurs after the life ends, and book value stays at salvage.

Why does declining balance start so high?

It applies 2/life to the full cost in year 1, so a 5-year asset starts at 40% of cost.

Can students use this calculator?

Yes, it is ideal for engineering economics and accounting coursework on depreciation methods.

How is SYD depreciation calculated for year 3 of 5?

Base × (5 − 3 + 1) / 15 = 22,500 × 3 / 15 = $4,500 with the standard example values.

What is accumulated depreciation?

The sum of all depreciation charged so far; book value equals cost minus accumulated depreciation.

Does the calculator support both SI and imperial units?

Yes. Depreciation inputs are unit-independent; costs are entered directly in dollars.

What if results show "---"?

One or more inputs are empty, zero where not allowed, or non-numeric. Check every field.

How do depreciation methods affect machine-hour rates?

Annual depreciation is divided by annual operating hours; accelerated methods raise early-year hourly charges.

Should I depreciate land?

No. Land is not depreciated because it does not get consumed; only improvements and equipment on it are depreciated.

What is the difference between SYD and declining balance?

Both front-load depreciation. SYD declines by a fixed step each year; declining balance applies a fixed rate to a shrinking balance.

Can I use this for leased equipment?

Depreciation applies to owned assets; for leases, apply the accounting standard for right-of-use assets instead.

How often should asset lives be reviewed?

Annually, and whenever technology or utilization changes the realistic service life.

Is there a mobile version?

Yes, the calculator is fully responsive and works on all devices.

Why do book value and resale value differ?

Book value follows a chosen accounting pattern; resale value follows the market, which accounts for condition, demand, and technology.

How does this relate to the Equipment Replacement Calculator?

Depreciation feeds annualized cost in replacement analysis; book value trends help time the replacement decision.

Where can I learn more about depreciation?

ISO 15686-5 covers life cycle costing, and ASME and AACE International publish asset economics guidance.

Related Calculators

Explore more calculators related to this topic.

Related Guides

Deepen your understanding with these educational resources.

ISO 15686-5 - Life Cycle Costing

International standard for asset cost over the full life

AACE International - Cost Engineering

Professional standards for depreciation and cost analysis

Glossary

Technical terms used in mortgage calculations explained in plain language.

Depreciable Base: Asset cost minus salvage value; the total amount subject to depreciation.
Straight-Line Depreciation: Equal annual depreciation: base divided by useful life.
Double Declining Balance: Accelerated method applying twice the straight-line rate to the remaining book value.
Sum-of-Years Digits: A declining-charge method using the sum of year digits as the denominator.
Book Value: Asset cost minus accumulated depreciation.
Salvage Value: Expected value of the asset at the end of its useful life.
Useful Life: The period over which an asset is expected to provide service.
Accumulated Depreciation: The total depreciation charged on an asset since acquisition.
MACRS: The US tax depreciation system using statutory class lives and conventions.

Authoritative References

Trusted sources and standards referenced by this calculator.

AACE International - Depreciation and Cost Standards NIST - Manufacturing Asset Management MIT OpenCourseWare - Engineering Economics and Depreciation ISO 15686-5 - Life Cycle Costing Engineering Toolbox - Depreciation Methods ASME - Asset Lifecycle Management

Applicable Standards

AACE 17R-97ISO 15686-5ASME Y14NIST GMPISO 9001

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Page Information

Last Updated:

2026-07-31

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.