Depreciation Adjusting Entries: Methods and Worked Examples
Period-end depreciation adjusting entries explained: the four depreciation methods (straight-line, double-declining-balance, units-of-production, sum-of-years-digits), when each is used, and a parallel worked example computing depreciation on a single $50,000 asset under all four methods to show how period-end entries differ.
Period-end depreciation adjusting entries explained: the four depreciation methods (straight-line, double-declining-balance, units-of-production, sum-of-years-digits), when each is used, and a parallel worked example computing depreciation on a single $50,000 asset under all four methods to show how period-end entries differ.
Learning Objectives
- ✓Explain why depreciation is required under accrual accounting
- ✓Identify the four primary depreciation methods
- ✓Compute depreciation under each method
- ✓Write correct adjusting entries for depreciation
- ✓Compare results across methods on a single worked asset
1. Why Depreciation Is an Adjusting Entry
When a company buys equipment for $50,000, no expense is recognized at purchase. The asset has future economic benefit over multiple periods, so the matching principle requires the cost to be allocated across those periods. Depreciation is that systematic allocation. Without depreciation, the income statement would show a massive expense in the purchase year and zero expense in subsequent years — distorting period-by-period performance. Depreciation smooths the cost across the useful life of the asset. The accounting mechanic: Depreciation Expense (income statement) is debited each period, and Accumulated Depreciation (a contra-asset, balance sheet) is credited. The asset itself remains at original cost on the balance sheet; the contra-asset accumulates over time. Net book value = Cost − Accumulated Depreciation. Depreciation is a non-cash expense — no cash leaves the company when it is recorded. This is why depreciation is added back when reconciling from net income to cash flow from operations under the indirect method. The cash outflow happened at purchase; depreciation just allocates that prior cash outflow across the useful life.
Key Points
- •Matching principle: allocate cost across useful life, not at purchase
- •Depreciation Expense (IS) debit; Accumulated Depreciation (contra-asset) credit
- •Net book value = Cost − Accumulated Depreciation
- •Depreciation is non-cash; added back in indirect method CF
- •Adjusting entry made at each period-end (monthly, quarterly, or annually)
2. The Four Primary Methods
Straight-Line. Equal depreciation in every period. (Cost − Salvage Value) / Useful Life = annual depreciation. The simplest and most common method. Used for assets with relatively constant economic productivity (buildings, office furniture). Double-Declining-Balance (DDB). Accelerated depreciation, higher in early years. Annual rate = 2 × (1 / Useful Life). Depreciation each year = Beginning Book Value × Rate. Salvage value is NOT subtracted in the calculation but caps the total depreciation (cannot depreciate below salvage). Used for assets that lose value rapidly in early years (computers, vehicles). Units-of-Production. Depreciation tied to actual usage rather than time. Depreciation per unit = (Cost − Salvage) / Total Estimated Units. Annual depreciation = Units used this period × Depreciation per unit. Used for assets where usage varies dramatically (manufacturing equipment, vehicles measured by miles). Sum-of-Years-Digits (SYD). Accelerated like DDB but with a different math. Denominator = sum of years (e.g., 5-year life: 5+4+3+2+1 = 15). Year 1 depreciation = (Cost − Salvage) × (5/15). Year 2 = (Cost − Salvage) × (4/15). And so on. Less common than DDB but appears on CPA exam.
Key Points
- •Straight-Line: equal allocation each period
- •Double-Declining-Balance: accelerated, 2× straight-line rate on book value
- •Units-of-Production: tied to actual usage, not time
- •Sum-of-Years-Digits: accelerated with year-fraction allocation
- •Choice depends on asset usage pattern and tax planning considerations
3. Method Comparison Table
The four methods compared at a glance. | Method | Pattern | When Used | Calculation | |---|---|---|---| | Straight-Line | Equal each period | Constant productivity (buildings, furniture) | (Cost − Salvage) / Life | | Double-Declining-Balance | Front-loaded | Rapid early decline (computers, vehicles) | Book Value × (2 / Life) | | Units-of-Production | Variable | Usage-driven (manufacturing, mileage) | (Cost − Salvage) / Total Units × Units Used | | Sum-of-Years-Digits | Front-loaded | CPA exam favorite (rarely in modern practice) | (Cost − Salvage) × Remaining Life / Sum of Years | For a 5-year asset, the year-1 depreciation rates compare as: Straight-line 20%, DDB 40%, SYD 33.3%. Front-loaded methods (DDB, SYD) recognize more expense early and less expense later, which can match the actual economic decline pattern of certain assets. Tax depreciation (MACRS in the US) is separate from book depreciation. Companies maintain two sets of depreciation schedules — one for financial reporting (book) and one for tax (MACRS, which is its own set of rates set by the IRS). This is why deferred tax liabilities exist on most balance sheets.
Key Points
- •Straight-line is most common in practice
- •DDB is accelerated; SYD also accelerated but less common
- •Units-of-production fits manufacturing equipment
- •Tax depreciation (MACRS) is separate from book depreciation
- •Deferred tax liabilities arise from book/tax depreciation differences
4. Parallel Worked Example: $50,000 Asset, 5-Year Life, $5,000 Salvage
Acme Corp purchases manufacturing equipment for $50,000. Estimated useful life: 5 years. Estimated salvage value: $5,000. Estimated total units of production: 100,000 units. Compute year-1 depreciation under all four methods. Straight-Line. Annual depreciation = ($50,000 − $5,000) / 5 = $9,000 per year. Year-1 entry: Depreciation Expense $9,000 debit; Accumulated Depreciation $9,000 credit. Same amount every year for five years. Total accumulated depreciation after 5 years: $45,000. Net book value at end of year 5: $5,000 (= salvage). Double-Declining-Balance. Rate = 2 × (1/5) = 40%. Year-1 depreciation = $50,000 × 40% = $20,000. Year-2 depreciation = ($50,000 − $20,000) × 40% = $12,000. Year-3: ($30,000 − $12,000) × 40% = $7,200. Year-4: ($18,000 − $7,200) × 40% = $4,320 — but check salvage limit. Cumulative after year-4: $20,000 + $12,000 + $7,200 + $4,320 = $43,520. Year-5 depreciation: limited to ($45,000 − $43,520) = $1,480 (to bring book value to salvage of $5,000). Total depreciation over 5 years: $45,000. Units-of-Production. Depreciation per unit = ($50,000 − $5,000) / 100,000 = $0.45/unit. If the asset is used 25,000 units in year 1, year-1 depreciation = 25,000 × $0.45 = $11,250. Year-2 entry depends on actual usage that year. Year-5 entry depends on remaining production until total of 100,000 units is reached or salvage is hit. Sum-of-Years-Digits. Sum of years for 5-year life = 5+4+3+2+1 = 15. Year-1 depreciation = ($50,000 − $5,000) × (5/15) = $15,000. Year-2 = $45,000 × (4/15) = $12,000. Year-3 = $9,000. Year-4 = $6,000. Year-5 = $3,000. Total = $45,000. Year-1 comparison: SL $9,000; DDB $20,000; UoP (at 25K units) $11,250; SYD $15,000. The choice of method dramatically affects period reporting but produces the same total depreciation ($45,000) over the asset life.
Key Points
- •All four methods produce same total depreciation over asset life
- •Period-by-period allocation differs dramatically
- •DDB has highest year-1 depreciation; SL has lowest constant amount
- •DDB requires salvage-value cap check in later years
- •Units-of-production varies based on actual usage
5. How AccountingIQ Helps With Depreciation Problems
Snap a photo of any asset purchase entry or depreciation schedule and AccountingIQ computes depreciation under all four methods, produces the full year-by-year schedule, and writes the period-end adjusting entries. For CPA FAR practice, the app generates problems at varying complexity (single asset, mixed methods across multiple assets, asset disposals with partial-year depreciation). AccountingIQ also handles deferred tax computations for book/tax depreciation differences. This content is for educational purposes only and does not constitute accounting advice.
Key Points
- •Computes depreciation under all four methods
- •Produces year-by-year schedules with accumulated depreciation
- •Writes period-end adjusting entries
- •Handles deferred tax book/tax differences
- •CPA FAR practice mode for depreciation problems
High-Yield Facts
- ★Matching principle drives depreciation: allocate cost across useful life
- ★Adjusting entry: Depreciation Expense DR; Accumulated Depreciation CR
- ★Accumulated Depreciation is a contra-asset (reduces asset on balance sheet)
- ★Net Book Value = Cost − Accumulated Depreciation
- ★Depreciation is non-cash (added back in indirect method CF)
- ★Straight-Line: (Cost − Salvage) / Life, equal each period
- ★Double-Declining-Balance: Book Value × (2/Life), accelerated, ignores salvage in calc but caps at salvage
- ★Units-of-Production: (Cost − Salvage) / Total Units × Units Used
- ★Sum-of-Years-Digits: (Cost − Salvage) × Remaining Life / Sum of Years
- ★All methods produce same total depreciation over asset life
- ★MACRS (tax) is separate from book depreciation
- ★Deferred tax liabilities arise from book/tax depreciation timing differences
Practice Questions
1. A $40,000 asset with $4,000 salvage and 4-year life. Compute year-1 straight-line depreciation.
2. A $20,000 asset with $2,000 salvage and 5-year life. Compute year-1 double-declining-balance depreciation.
3. A delivery truck cost $30,000, salvage $3,000, expected 200,000 total miles. The truck was driven 40,000 miles in year 1. Compute year-1 units-of-production depreciation.
4. Why is depreciation added back when reconciling net income to operating cash flow?
5. A $50,000 asset, 5-year life, $5,000 salvage, sum-of-years-digits method. Compute year-3 depreciation.
FAQs
Common questions about this topic
For book purposes, the method should reflect the pattern of economic benefit consumption. Constant productivity → straight-line. Rapid early productivity then decline → DDB or SYD. Usage-driven → units-of-production. Most companies default to straight-line for simplicity unless a clearly different pattern justifies an accelerated method. For tax purposes, MACRS rates are imposed by the IRS, so the choice does not exist. The financial-reporting choice is made by management and disclosed in the footnotes.
A gain or loss is recognized for the difference between proceeds and net book value. If the asset cost $50,000 with accumulated depreciation of $30,000 (net book value $20,000) and is sold for $25,000, the gain is $5,000. Journal entry: Cash $25,000 debit; Accumulated Depreciation $30,000 debit; Equipment $50,000 credit; Gain on Sale $5,000 credit. The gain appears on the income statement as a non-operating item.
Rarely, and it requires special accounting. A change in depreciation method is treated as a change in accounting estimate (not a change in accounting principle) and applied prospectively. The remaining net book value is allocated over the remaining useful life under the new method. Disclosure in footnotes is required. Companies almost never change methods because of the accounting complexity and the disclosure burden.
Land is not depreciated. It has indefinite useful life (the assumption is land does not wear out). Buildings ON land ARE depreciated. When a company buys land and a building together, the purchase price is allocated between them (typically based on appraisal or assessed value ratio), and only the building portion is depreciated. Land improvements (parking lots, landscaping) are depreciated separately because they do have limited useful lives.
All three are systematic allocations of asset cost over time. Depreciation applies to tangible assets (equipment, buildings, vehicles). Amortization applies to intangible assets (patents, trademarks, software). Depletion applies to natural resources (oil reserves, mineral deposits, timber). The mechanics are the same: a periodic expense and corresponding reduction of the asset (or accumulated contra-asset). Some companies present all three on a combined "depreciation and amortization" line.
Snap a photo of any asset purchase entry and AccountingIQ produces depreciation schedules under all four methods (SL, DDB, UoP, SYD), writes period-end adjusting entries, and handles partial-year depreciation for mid-year acquisitions or disposals. For CPA FAR practice, the app generates problems at varying complexity with full solutions. AccountingIQ also produces deferred tax calculations when book and tax depreciation differ. This content is for educational purposes only and does not constitute accounting advice.