Amortization Calculator

About the Amortization Calculator

An amortization calculator generates a complete payment-by-payment schedule for any loan — showing the exact split between principal and interest for every single payment over the entire loan life. This detailed view, called a loan amortization schedule or amortization table, is one of the most financially revealing documents a borrower can have. It shows you precisely how much of your monthly payment is building equity versus paying interest costs, when you cross specific equity milestones, how much total interest you will pay over the life of the loan, and exactly how much extra payments save you. The word "amortization" comes from the Latin "amort" meaning death — in financial terms, it refers to the gradual killing off of a debt through regular payments. Every mortgage amortization schedule, auto loan amortization, student loan repayment plan, and personal loan follows this same mathematical structure: fixed monthly payments that are dominated by interest in early years and dominated by principal reduction in later years. Understanding amortization is essential knowledge for every borrower, particularly homeowners, where the amortization schedule reveals that a 30-year mortgage at 7% charges approximately 85% interest and only 15% principal in the very first payment — a fact that motivates millions of homeowners to make extra payments once they understand it. Our calculator accepts any loan amount, interest rate, and term, and produces an interactive amortization table that you can scroll through month by month or export for tax and financial planning purposes.

How It Works

Each monthly payment in an amortising loan is constant (for fixed-rate loans), but its composition changes every single month. Here is how each payment is calculated: Step 1 — Monthly Interest Charge = Remaining Balance x (Annual Rate / 12). Step 2 — Principal Payment = Total Monthly Payment minus Monthly Interest Charge. Step 3 — New Balance = Previous Balance minus Principal Payment. This cycle repeats for every month of the loan. Example: a $200,000 loan at 6.5% over 30 years has a fixed monthly payment of $1,264. In Month 1: Interest = $200,000 x (0.065/12) = $1,083. Principal = $1,264 minus $1,083 = $181. New balance = $199,819. In Month 120 (year 10): balance is now approximately $175,000. Interest = $175,000 x 0.005417 = $948. Principal = $1,264 minus $948 = $316. By Month 300 (year 25): balance is approximately $75,000. Interest = $406. Principal = $858 — the majority of the payment is now reducing the balance. The total interest paid over all 360 payments = $255,000 — more than the original loan amount.

Tips & Best Practices

• ✓The amortization schedule reveals that on a 30-year mortgage at 6.5%, you do not reach 50% equity through payments alone until approximately year 21 — the first 21 years of payments are majority interest.
• ✓Making one extra full monthly payment per year (13 instead of 12) reduces a 30-year mortgage to approximately 25 years and saves tens of thousands of dollars in interest — the amortization table shows exactly how much.
• ✓Bi-weekly payments (half your monthly payment every two weeks) result in 26 half-payments = 13 full payments per year automatically, producing the same accelerated payoff benefit as one extra annual payment.
• ✓Lump-sum extra payments applied directly to principal reduce the balance immediately and eliminate all future interest that would have accrued on that balance — the savings compound across the remaining loan term.
• ✓For tax purposes: the amortization schedule shows the exact amount of mortgage interest paid in each calendar year, which is the figure needed for Schedule A itemised deductions (if you itemise) in the USA.
• ✓Loan amortization schedule note: if you refinance, your amortization clock resets — you start back at the beginning with mostly-interest payments on the new loan.
• ✓Negative amortization occurs when a payment is less than the monthly interest charge — the unpaid interest is added to the balance, making the loan grow larger instead of smaller. Some adjustable-rate mortgages (ARMs) have this risk.
• ✓The amortization table is essential for financial planning: it shows your projected loan balance at any future date, allowing you to calculate home equity at any time and plan cash-out refinancing or HELOCs accurately.

Who Uses This Calculator

Homeowners use the loan amortization schedule to understand exactly where their monthly mortgage payment goes — the revelation that early payments are primarily interest, not equity-building, motivates many to make additional principal payments. Tax preparers and accountants use amortization tables to extract the exact mortgage interest figure for Schedule A itemised deductions, since mortgage interest is reported by the lender but the amortization table provides a cross-check. Real estate investors use amortization schedules to model cash-on-cash returns and equity growth projections for rental property investments, tracking when accumulated equity enables a cash-out refinance for portfolio expansion. Homeowners planning to sell use the table to project their loan balance at the anticipated sale date, allowing accurate net proceeds calculations after realtor commissions and closing costs. Financial advisors incorporate amortization calculations into comprehensive wealth-building plans, especially the comparison between accelerated mortgage payoff versus investing extra funds in the market. Students in personal finance and real estate courses use amortization schedules as a foundational learning exercise because they concretely demonstrate the mathematics of compound interest, time value of money, and the long-term cost of debt.