Amortization is the process of spreading the cost of an intangible asset over its useful life, similar to depreciation but for non-physical assets like patents, trademarks, copyrights, and acquired goodwill.
Straight-Line Amortization = Intangible Asset Cost ÷ Useful Life
Loan Payment = P × [r(1+r)^n] ÷ [(1+r)^n − 1]
A pharmaceutical company acquires a patent for $50 million with 10 years remaining until expiration. Annual amortization = $50M ÷ 10 = $5M/year. Each year, the patent's book value decreases by $5M, and the income statement records a $5M amortization expense. After 10 years, the patent is fully amortized (book value = $0), even though it may still generate revenue if legally extended. For loan amortization: a $300,000 mortgage at 6% for 30 years has a monthly payment of $1,799. In the first month, $1,500 goes to interest and only $299 to principal. By year 25, the payment shifts to approximately $400 interest and $1,399 principal.
Amortization serves two main purposes in finance. For intangible assets, it spreads the cost over the asset's useful life (like depreciation does for physical assets). For loans, it creates a schedule where each payment covers both interest and principal repayment, with the interest portion declining over time as the principal balance shrinks. Under current U.S. GAAP rules, goodwill is no longer amortized but is instead tested annually for impairment — a significant change that affects how acquisitions appear on financial statements.
Amortization of intangibles is a major factor in analyzing companies that have grown through acquisitions. When Salesforce acquired Slack for $27.7 billion in 2021, approximately $15-20 billion was allocated to intangible assets and goodwill. The amortization of these intangibles reduces Salesforce's reported earnings by billions annually, making its P/E ratio appear astronomical. However, like depreciation, amortization is a non-cash expense — Salesforce's actual cash flow is much higher than its net income suggests.
For loan amortization, the front-loaded interest structure has important implications. In the early years of a 30-year mortgage, approximately 70-80% of each payment goes to interest, meaning the borrower builds equity very slowly. This is why making extra principal payments in the early years has an outsized effect on total interest paid. An extra $100/month in principal payments on a $300,000 mortgage can save over $40,000 in total interest and shorten the loan by 4-5 years.
Disney (DIS) amortizes the rights to its massive content library. When Disney produces a movie for $200 million, the cost is amortized over the expected revenue-generating life of the film — typically 5-10 years for theatrical, streaming, and licensing revenue. Disney also amortizes the $71 billion Fox acquisition intangibles over various periods. Understanding this amortization schedule is crucial for evaluating Disney's true earnings power, as the non-cash charges obscure the underlying cash generation.
Add back amortization when valuing acquisition-heavy companies: Companies like Meta, Salesforce, and Disney report lower earnings due to acquisition amortization. EBITDA and adjusted EPS provide a clearer picture of cash generation.
Check for goodwill impairment risk: Since goodwill isn't amortized under GAAP, watch for impairment charges. A goodwill impairment means the company overpaid for an acquisition. This is a non-cash charge but signals poor capital allocation.
For mortgages, model extra principal payments: Even small additional monthly payments dramatically reduce total interest. Use an amortization calculator to see the impact of paying $100-200 extra per month.
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Try Amortization Calculator →What is the difference between amortization and depreciation?
Depreciation applies to physical assets (buildings, equipment, vehicles). Amortization applies to intangible assets (patents, trademarks, software licenses). Both spread the cost over the asset's useful life. If you buy a truck, you depreciate it. If you buy a software license, you amortize it. The accounting treatment is essentially the same.
How does amortization affect taxes?
Amortization reduces taxable income, just like depreciation. If a company amortizes $100K of intangible assets per year, that's $100K less in pre-tax income. At a 21% corporate tax rate, this saves $21K in taxes annually. This is why companies are motivated to identify and amortize all eligible intangible assets.
What is loan amortization?
In lending, amortization refers to spreading loan payments over time. An amortizing loan (like a mortgage) has equal monthly payments, but early payments are mostly interest while later payments are mostly principal. This contrasts with interest-only loans where you pay only interest and owe the full principal at maturity.