Depreciation and amortization reduce a company's reported net income without consuming any actual cash. These accounting concepts spread the cost of tangible assets and intangible assets over their useful lives. Knowing how these charges work helps investors assess true earning power from the financial statements.
What Is Depreciation?
Depreciation allocates the cost of a tangible asset over its useful life. Buildings, machinery, vehicles, and equipment all lose value as they age and wear out. Instead of expensing the full asset cost at once, companies spread it over the years the asset is in use. This matching principle is one of the fundamental accounting concepts in financial reporting.
Each year, the company records a depreciation expense on the income statement. That expense reduces net income for the period. At the same time, accumulated depreciation grows on the balance sheet, reducing the book value of the fixed asset. The cash the company spent on the asset left the business at the time of purchase. The annual depreciation expense is purely an accounting entry that reflects how assets lose value over time.
What Is Amortization?
Amortization works the same way as depreciation but applies to intangible assets. Patents, trademarks, customer lists, software licenses, and goodwill all qualify as intangible assets that companies may amortize. The company follows an amortization schedule that spreads the asset cost across the expected period of benefit.
Like depreciation, amortization reduces net income without reducing cash. A company that buys a patent for 50 million and spreads it over 10 years records 5 million per year. That 5 million lowers reported earnings but no cash leaves the company each year for that charge. The cash went out when the patent was purchased. The amortization schedule simply allocates that initial cost across future periods.
Common Depreciation Methods
The straight line method is the simplest approach. It divides the asset cost minus any salvage value by the useful life in years. A 1 million machine with a 10 year life creates 100 thousand in yearly depreciation expense. The charge stays the same every year, making this method easy to forecast and model.
The double declining balance method front-loads the depreciation expense. It applies twice the straight line rate to the remaining book value each year. Early years carry higher charges, and later years carry lower ones. This fits assets over time that lose value fast, like tech gear that goes outdated in a few years.
The sum of the years digits method also provides accelerated depreciation but uses a different formula. It uses fractions based on the remaining useful life. The sum of the years digits forms the base of each fraction. A 5 year asset uses fractions of 5/15, 4/15, 3/15, 2/15, and 1/15. The years digits method produces higher charges early and lower charges later, similar to the double declining balance method.
Companies choose among these depreciation methods based on how each fixed asset actually loses value. The choice affects reported net income and the balance sheet carrying value. Different methods produce different earnings profiles even when the underlying business performance stays exactly the same. Investors should note which methods each company uses and how those choices compare to industry peers.
How Depreciation Affects Stock Valuation
Higher depreciation expense reduces reported net income. Lower net income can make a company look less profitable than its cash generation would suggest. This disconnect matters most for capital-intensive businesses that carry large amounts of tangible assets like factories, pipelines, or fleets of vehicles.
Investors often add depreciation and amortization back to net income to calculate EBITDA. This metric strips out the impact of non-cash charges and provides a cleaner view of operating performance. Companies with heavy depreciation loads may show modest net income but generate strong cash flow because the depreciation expense does not consume real money.
The price to earnings ratio can mislead investors when companies carry large depreciation charges. Two companies with identical cash flows may report very different earnings depending on their depreciation methods and asset ages. Comparing price to cash flow or enterprise value to EBITDA often produces more accurate valuation comparisons in asset-heavy industries.
Accumulated Depreciation on the Balance Sheet
Accumulated depreciation appears on the balance sheet as a reduction to gross fixed asset values. If a company owns 5 billion in gross property and equipment and has 3 billion in accumulated depreciation, the net fixed asset value equals 2 billion. This net figure reflects the remaining book value of the company's tangible assets after accounting for wear and aging.
A high ratio of accumulated depreciation to gross assets suggests the company's equipment is old. Aging assets may need replacement soon, requiring significant long term capital spending. A low ratio suggests newer assets that should provide productive service for many more years. Investors who track this ratio across time can anticipate future capital expenditure cycles.
Impact on Free Cash Flow
Free cash flow equals operating cash flow minus capital expenditures. Because depreciation and amortization are non-cash charges that reduce net income but get added back in the cash flow calculation, they create a gap between reported earnings and actual cash generation. Companies with large depreciation charges often produce free cash flow well above their net income.
This matters for dividend investors. A company may report net income of 200 million after 300 million in depreciation expense. Operating cash flow might reach 500 million because the depreciation gets added back. If capital spending runs 250 million, free cash flow equals 250 million, far above the 200 million in net income. The company has more cash available for dividends than the income statement alone would suggest.
However, capital spending must eventually replace worn-out assets. A company that reduces maintenance spending to inflate short-term free cash flow may face a catch-up period where heavy spending compresses future cash generation. Compare depreciation expense to capital expenditures over several years. If spending consistently falls below depreciation, the company may be underinvesting in its long term asset base.