Depreciation Adjusting Entry (Straight-Line)
Learn how to record straight-line depreciation adjusting entries for fixed assets. Covers the calculation formula, monthly vs. annual entries, the role of Accumulated Depreciation, and book value tracking.
Learn how to record straight-line depreciation adjusting entries for fixed assets. Covers the calculation formula, monthly vs. annual entries, the role of Accumulated Depreciation, and book value tracking.
Scenario
On January 1, Year 1, Oakmont Manufacturing purchases equipment for $48,000. The equipment has an estimated salvage value of $6,000 and a useful life of 7 years (84 months). The company prepares monthly financial statements and uses straight-line depreciation.
Journal Entries
January 1 — Record equipment purchase. The full cost is capitalized as a fixed asset, not expensed, because the benefit extends over multiple years.
| Account | Debit | Credit |
|---|---|---|
| Equipment | $48,000 | |
| Cash | $48,000 |
January 31 — Record monthly depreciation. Depreciable base = $48,000 − $6,000 = $42,000. Monthly expense = $42,000 / 84 months = $500.
| Account | Debit | Credit |
|---|---|---|
| Depreciation Expense | $500 | |
| Accumulated Depreciation — Equipment | $500 |
This $500 entry repeats at the end of each month for 84 months. After Year 1 (12 entries), Accumulated Depreciation = $6,000 and book value = $48,000 − $6,000 = $42,000.
Explanation
Depreciation systematically allocates the cost of a long-lived asset over its useful life. The equipment provides value to Oakmont for 7 years, so the matching principle requires spreading the $42,000 depreciable cost across those 84 months rather than expensing $48,000 in Year 1. The straight-line method divides the depreciable base (cost minus salvage value) evenly over the useful life. Accumulated Depreciation is a contra-asset — it carries a credit balance that offsets the Equipment account's debit balance. Using a contra-asset instead of directly reducing Equipment preserves the original cost on the balance sheet, which is important for disclosure, insurance purposes, and calculating gains or losses on disposal. After 3 years: Equipment stays at $48,000, Accumulated Depreciation is $18,000 (36 × $500), and book value (also called carrying value or net book value) is $30,000. At the end of 7 years, Accumulated Depreciation reaches $42,000 and book value equals the $6,000 salvage value — depreciation stops at that point.
Variations
Annual entry instead of monthly: Debit Depreciation Expense $6,000, Credit Accumulated Depreciation $6,000 once at year-end. Same total result, less administrative work, but less accurate interim financial statements.
Mid-year purchase: If equipment is purchased April 1, Year 1 depreciation covers 9 months (April through December): $500 × 9 = $4,500. Some companies use a half-year convention instead, recognizing 6 months regardless of purchase date.
Double-declining balance method: Year 1 rate = 2 / 7 = 28.57%. Year 1 expense = $48,000 × 28.57% = $13,714. This accelerates expense recognition into early years when the asset provides the most value.
Common Mistakes to Avoid
- ✗Crediting the Equipment account directly instead of Accumulated Depreciation — this destroys the historical cost record and violates GAAP presentation requirements
- ✗Including salvage value in the depreciable base — only the amount above salvage is depreciated. Cost minus salvage equals the depreciable base
- ✗Continuing to depreciate below salvage value — depreciation stops when book value reaches the estimated salvage value, even if the asset is still in use
- ✗Expensing the full equipment cost at purchase — capitalization is required when the asset will benefit more than one accounting period
FAQs
Common questions about this journal entry
Accumulated Depreciation is a contra-asset that preserves the original cost of the equipment on the balance sheet. This is important because users need to see both the gross cost (what was paid) and the total depreciation (how much has been allocated). It also matters for calculating gain or loss on disposal, insurance claims, and tax reporting.
Annual Depreciation = (Cost − Salvage Value) / Useful Life in Years. For monthly depreciation, divide the annual amount by 12. Oakmont's calculation: ($48,000 − $6,000) / 7 = $6,000 per year, or $500 per month. The 'straight line' name comes from the fact that the same amount is expensed every period.
Stop recording depreciation. The asset remains on the books at its salvage value (cost minus total accumulated depreciation) until it is disposed of. A fully depreciated asset that's still productive doesn't generate additional expense — the cost allocation is complete.
For tax purposes, companies often use accelerated methods (like MACRS in the U.S.) that front-load depreciation expense, reducing taxable income in early years. Book depreciation (for financial statements) and tax depreciation (for IRS) are calculated independently, which creates temporary differences that lead to deferred tax assets or liabilities.
All three allocate cost over useful life, but they apply to different asset types. Depreciation is for tangible assets (equipment, buildings, vehicles). Amortization is for intangible assets (patents, copyrights, software). Depletion is for natural resources (oil, timber, minerals). The journal entry structure is similar for all three.