Amortization
The systematic allocation of an intangible asset's cost or a loan's principal over a defined period.
Amortization has two related but distinct meanings in finance: in accounting, it refers to the gradual write-off of an intangible asset's cost over its useful life; in lending, it refers to the process of repaying a loan through scheduled periodic payments that cover both interest and principal, reducing the outstanding balance to zero over the loan term.
In accounting: Intangible asset amortization spreads the cost of finite-life intangible assets (patents, customer lists, software licenses, non-compete agreements, trademarks with defined terms) over their expected useful lives. The calculation mirrors straight-line depreciation: (Cost − Residual Value) ÷ Useful Life = Annual Amortization Expense. Under GAAP, intangible assets must be assessed for useful life — those with finite lives are amortized; those with indefinite lives are not amortized but are tested for impairment. Goodwill is a special case — not amortized under public company GAAP, but private companies may elect to amortize over 10 years.
In lending: Loan amortization describes how mortgage, auto loan, student loan, and other installment debt is paid down over time. In a standard amortizing loan, each payment consists of interest (calculated on the outstanding balance) and principal (the remainder). Early payments are interest-heavy; later payments shift toward principal as the balance declines. An amortization schedule shows each payment's interest/principal split and the remaining balance after each payment.
For example, a $300,000, 30-year mortgage at 7% has a monthly payment of $1,996. Month 1: $1,750 interest + $246 principal. Month 360: $14 interest + $1,982 principal. This amortization pattern is why additional early principal payments dramatically shorten mortgage terms and reduce total interest paid.
Interest-only loans (non-amortizing) require only interest payments during an initial period, with the full principal due as a balloon payment — common in commercial real estate financing and some jumbo mortgages.
FAQs
What is an amortization schedule and how do I use it?
An amortization schedule is a table showing each periodic payment for a loan, broken into interest and principal components, with the remaining balance after each payment. Use it to understand how much of each mortgage or loan payment reduces debt vs. pays interest, determine the impact of extra principal payments, calculate the total interest cost over the loan's life, and find the balance at any given point for refinancing decisions.
What happens if I make extra payments on an amortizing loan?
Extra principal payments reduce the outstanding balance, which reduces future interest charges (since interest is calculated on the remaining balance). This can substantially shorten the loan term and reduce total interest paid. On a 30-year mortgage, adding $200/month to principal payments can eliminate 4–6 years of payments and save tens of thousands in interest, depending on the rate and balance.
What is negative amortization?
Negative amortization occurs when the required loan payment is less than the interest accruing in the period, causing the outstanding balance to increase rather than decrease. Common in certain adjustable-rate mortgages (ARMs) with payment caps. The unpaid interest is added to the loan balance — the borrower owes more than they originally borrowed. This was a contributing factor in the 2008 mortgage crisis.
Related Terms
Depreciation
The systematic allocation of a tangible asset's cost over its useful life, reducing its book value on the balance sheet each period.
Intangible Assets
Non-physical assets with economic value including patents, trademarks, copyrights, software, customer relationships, and brand names.
Goodwill
An intangible asset representing the premium paid in an acquisition above the fair market value of the target's identifiable net assets.
EBITDA
Earnings Before Interest, Taxes, Depreciation, and Amortization — a proxy for operating cash generation used in valuation and financial analysis.
