Asset Cost and Straight-Line Depreciation
Learning objectives
After this section you will be able to:
- Determine an asset's depreciable cost basis.
- Calculate straight-line depreciation and book value.
- Distinguish accounting allocation from market value.
Real-life situation
A shared workshop buys equipment
A hypothetical Philadelphia workshop buys a machine for $9,000, pays $600 delivery and $400 installation, and expects five years of service with a $1,000 residual value. It is ready for use at the start of the first year.
Machine record
- Purchase price: $9,000
- Delivery: $600; installation: $400
- Recorded cost: $10,000
- Estimated residual value: $1,000
- Estimated useful life: 5 years
- Straight-line depreciation: $1,800 per full year
The concept
A long-lived business asset helps operations beyond the current period. Its recorded cost generally includes the purchase price and necessary costs to bring it to the location and condition required for use. This illustration capitalizes delivery and installation; routine later maintenance is treated separately.
Depreciable amount is recorded cost minus estimated residual value. Residual value is the expected amount remaining at the end of the useful life under the estimates used. Neither the life nor the residual is a promise; actual outcomes may differ.
Straight-line depreciation allocates the same depreciable amount to each full year. Accumulated depreciation adds all depreciation recorded so far, while book value equals cost minus that accumulated amount. Under unchanged estimates, the scheduled ending book value is the residual value, not necessarily zero.
Depreciation is an allocation of cost, not an appraisal and not a cash savings account. A machine's market value may rise or fall differently from its book value. For partial years, this section uses an explicitly stated months-in-service fraction; real policies and tax rules may use different conventions.
Spread depreciable cost over useful life
- 1
Asset cost
$9,000 + $600 + $400 = $10,000
- 2
Depreciable base
$10,000 − $1,000 residual = $9,000
- 3
Annual expense
$9,000 ÷ 5 years = $1,800
Money Words
Plain-language words you will use in this lesson — learn them before we reach the formulas.
depreciation
The way a costly item, such as a machine, loses value and its cost is spread over its useful life.
asset
Something valuable that a person or business owns, like cash, equipment, or a building.
liability
Money or obligations a person or business owes to others.
Key terms
- Capitalized cost
- An amount recorded as part of an asset rather than expensed immediately.
- Useful life
- The estimated period over which an asset benefits the business.
- Residual value
- The estimated value remaining at the end of the useful life.
- Depreciable amount
- Recorded cost minus estimated residual value.
- Accumulated depreciation
- Total depreciation recorded on an asset to date.
- Book value
- Recorded asset cost minus accumulated depreciation in this simplified model.
Formulas & rules
Recorded cost
Cost = purchase price + necessary delivery + necessary installation
Straight-line expense
Annual depreciation = (cost − residual value) ÷ useful life
Book value
Book value = cost − accumulated depreciation
Partial-year expense
Partial-year depreciation = annual depreciation × months in service ÷ 12
The convention used in these examples.
Worked examples
Find the workshop machine's recorded cost and annual straight-line depreciation.
Solution
- 1Recorded cost: $9,000 + $600 + $400 = $10,000.
- 2Depreciable amount: $10,000 − $1,000 = $9,000.
- 3Annual expense: $9,000 ÷ 5 = $1,800.
Answer: Record the machine at $10,000 and allocate $1,800 per full year.
Find accumulated depreciation and book value after three full years.
Solution
- 1Annual straight-line depreciation is $1,800.
- 2Accumulated depreciation: 3 × $1,800 = $5,400.
- 3Book value: $10,000 − $5,400 = $4,600.
- 4Remaining depreciable amount: $4,600 − $1,000 = $3,600.
Answer: Accumulated depreciation is $5,400 and book value is $4,600, leaving two $1,800 full-year allocations.
Practice exercises 17.1
- Find book value after two full years.
- The machine is first used halfway through a year. Under the stated six-month convention, find first-year depreciation.
- Find accumulated depreciation and book value after five full years.
- What percent of recorded cost is the $1,000 residual estimate?
- A routine $200 maintenance bill occurs in year 2. Under the stated policy, does it increase the machine's recorded cost?
Recap quiz 17.1
Section 17.1 recap
- Depreciate cost minus residual, not automatically the entire cost.
- Book value, market value, and cash on hand are different quantities.
Answer key with explanations: Section 17.1
Practice exercises
- Accumulated depreciation = 2 × $1,800 = $3,600. Book value = $10,000 − $3,600 = $6,400.
- $1,800 × 6 ÷ 12 = $900. Book value at that year-end is $10,000 − $900 = $9,100.
- Accumulated depreciation = 5 × $1,800 = $9,000. Book value = $10,000 − $9,000 = $1,000, the estimated residual.
- $1,000 ÷ $10,000 × 100 = 10%. The remaining 90%, or $9,000, is depreciable.
- No. Record the $200 as maintenance expense under this simplified policy; cost stays $10,000 and scheduled annual depreciation stays $1,800.
Recap quiz
- $9,000: $10,000 cost − $1,000 residual = $9,000.
- $1,800: $9,000 ÷ 5 = $1,800.
- Cost minus accumulated depreciation in this model: Book value is an accounting amount, not a market-price estimate.