The Mortgage Amortization Calculator produces a complete amortization schedule : a table showing exactly how each monthly payment is divided between interest and principal, and what your remaining loan balance will be after every single payment. This schedule is fundamental to understanding how mortgages work and is essential for financial planning, refinancing decisions, and tax reporting. In a fully amortizing mortgage, every payment is the same dollar amount, but the composition of that payment shifts dramatically over time. In month 1 of a 30-year loan at 7%, approximately 83% of the payment is interest. By month 360, nearly 100% is principal. This front-loading of interest is why early payoff and refinancing decisions have such a large impact on total interest cost. The amortization schedule also reveals equity milestones : when you'll reach 20% equity (enabling PMI cancellation), when you'll reach 50% equity (a common refinancing evaluation point), and when the crossover point occurs where principal exceeds interest in each payment. For most 30-year mortgages at current rates, this crossover doesn't happen until year 18–20. Tax planning also relies on amortization data. The interest portion of each payment is potentially deductible (if you itemize), and the exact interest amount varies each year. The annual interest summary in this calculator provides the per-year figures needed for Schedule A tax reporting or for verifying lender-issued Form 1098 statements.
Enter your details and click Calculate to see results.
Saved Presets is a Supporter feature.
Tool History is a Supporter feature.
Tool Notes is a Supporter feature.
Input the loan amount, annual interest rate, and loan term in years.
Click Calculate to generate a complete payment-by-payment amortization table showing principal, interest, and remaining balance.
Switch between the full monthly schedule and the annual summary view depending on your planning needs.
Check total interest paid, monthly payment amount, payoff date, and the crossover month when principal exceeds interest.
Monthly payment M = P × [r(1+r)^n] / [(1+r)^n − 1]. Each month: Interest = Balance × r; Principal = M − Interest; New Balance = Balance − Principal. This process repeats for each of the n payments until the balance reaches zero. The formula ensures equal payments throughout the term while gradually shifting the interest/principal split.
Month 1 on a $300,000 30-year loan at 7%: Interest = $300,000 × 0.005833 = $1,750; Principal = $1,996 − $1,750 = $246. Month 180 (year 15): Balance ≈ $222,000; Interest = $1,295; Principal = $701. Month 360 (final): Interest ≈ $12; Principal ≈ $1,985. Total interest paid: $418,527 : 140% of the original loan amount.
Borrowers with less than 20% down payment typically pay PMI (Private Mortgage Insurance). PMI can be cancelled when the loan balance drops to 80% of the original appraised value (per the Homeowners Protection Act). The amortization schedule shows exactly which payment brings the balance to this threshold, enabling borrowers to request PMI cancellation proactively.
The annual amortization summary shows total interest paid each calendar year. This is the figure that may be deductible on Schedule A if you itemize deductions. Your lender also provides Form 1098 annually with this figure; this calculator allows you to verify that figure or project future-year interest for tax planning purposes.
An amortization schedule is a table listing every payment over the life of a loan, showing how each payment is divided between interest and principal, and the remaining balance after each payment. It demonstrates how a fixed monthly payment gradually transitions from mostly-interest to mostly-principal over the loan term.
