Depreciation

Depreciation is the process of systematically allocating the cost of a tangible fixed asset over its useful life. It reflects the wear and tear, aging, or obsolescence of physical assets used in business operations, such as machinery, buildings, vehicles, and equipment.

Depreciation isn’t about market value decline—it’s about accounting for how long an asset provides value to your business.

It is a non-cash expense that reduces reported earnings while providing tax benefits and true reflection of asset utility over time.

Why Depreciation Matters

Matches cost with revenue in each accounting period
Spreads out large capital expenditures over time
Impacts net income, taxable income, and asset valuation
Helps assess asset performance and replacement timing

Depreciation vs Amortization vs Depletion

Term	Applies To	Example
Depreciation	Tangible assets	Machinery, vehicles
Amortization	Intangible assets	Patents, software
Depletion	Natural resources	Oil fields, mineral mines

Key Inputs in Depreciation

Cost of Asset
Useful Life (in years or periods)
Residual (Salvage) Value
Depreciation Method

Common Depreciation Methods

Method	Description
Straight-Line	Equal expense each period
Declining Balance	Higher expense in early years
Double Declining Balance	Accelerated version of declining balance
Units of Production	Based on actual usage or output
Sum-of-the-Years’-Digits	Front-loaded depreciation with a fixed declining pattern

Straight-Line Depreciation Formula

Depreciation Expense = (Cost − Salvage Value) / Useful Life

Example:

Cost = $50,000
Salvage Value = $5,000
Useful Life = 5 years
→ Depreciation per year = ($50,000 − $5,000) / 5 = $9,000

Declining Balance Method (DDB)

Depreciation Expense = Book Value × (2 / Useful Life)

Provides accelerated depreciation; useful for tax benefits or tech assets that lose value quickly.

Units of Production Formula

Depreciation per Unit = (Cost − Salvage Value) / Total Estimated Output  
Annual Depreciation = Depreciation per Unit × Units Produced This Year

Ideal for machinery or vehicles where wear is based on usage.

Depreciation in Financial Statements

Income Statement: Appears as depreciation expense
Balance Sheet: Accumulates in contra-asset account “Accumulated Depreciation”
Cash Flow Statement: Added back to net income (non-cash expense)

Journal Entry for Depreciation

Dr. Depreciation Expense      $X  
    Cr. Accumulated Depreciation  $X

No cash is exchanged—this is purely an accounting adjustment.

Tax Depreciation vs Book Depreciation

Type	Purpose	Governed By
Book Depreciation	Financial reporting	GAAP or IFRS standards
Tax Depreciation	Tax calculation	IRS (MACRS), local tax codes

Tax depreciation methods (like MACRS in the U.S.) often accelerate expense recognition to reduce taxable income.

Depreciation Schedule Example

Year	Beginning Book Value	Depreciation	Ending Book Value
1	$50,000	$9,000	$41,000
2	$41,000	$9,000	$32,000
…	…	…	…
5	$14,000	$9,000	$5,000 (salvage)

Asset Disposal and Depreciation

When disposing of a depreciated asset:

Gain or loss is calculated based on book value vs sale price
Remove asset from books:

Dr. Cash / Receivable  
Dr. Accumulated Depreciation  
    Cr. Asset Account  
    Cr./Dr. Gain or Loss on Disposal

Depreciation in Excel

Use the SLN, DDB, or SYD functions:

=SLN(cost, salvage, life)
=DDB(cost, salvage, life, period)
=SYD(cost, salvage, life, period)

These formulas automate complex calculations for consistent financial reporting.

Limitations of Depreciation

Based on estimates (useful life, salvage value)
May not reflect actual market value decline
Doesn’t account for technological obsolescence
Can differ between book and tax purposes

Final Thoughts

Depreciation is a foundational concept in accounting and finance. It helps spread the cost of long-term assets across their productive life, aligns expenses with revenue, and facilitates more accurate financial analysis.