Mortgage Amortization Calculator
See your monthly payment and interest breakdown over the life of your loan.
Monthly Payment
$0
Total Interest
$0
| Year | Interest | Principal | Remaining Balance |
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What this calculator does
If you are planning to buy a home or refinance an existing loan, understanding how your monthly payment is split between principal and interest is essential. This calculator breaks down the total cost of borrowing by projecting a complete amortization schedule over the lifespan of your mortgage. By inputting your target loan amount, expected interest rate, and loan term, it automatically computes your fixed monthly payment and total lifetime interest costs. This tool is designed for homebuyers and homeowners who want a clear, mathematically precise view of their future debt obligations without needing complex spreadsheet formulas.
How the math works
Mortgage amortization relies on the standard annuity formula, where the principal balance is multiplied by a periodic interest rate to determine the interest portion of each monthly payment. As you make payments over time, the interest portion decreases, and the principal portion increases. The underlying mathematics align with the official guidelines outlined by the Consumer Financial Protection Bureau (CFPB) and IRS Publication 936 for home mortgage interest deduction rules. For the 2026 tax year, you can reference the IRS standard deduction limitations when estimating tax benefits. The calculator computes this exact trajectory, generating a year-by-year summary so you can anticipate the exact principal reduction across the loan term.
Worked example
Imagine you take out a $350,000 mortgage at a fixed 6.5% interest rate over a 30-year term. Using the calculator's internal formulas, your fixed monthly payment for principal and interest combined is exactly $2,212. Over the course of the 30-year schedule, you will pay a total of $446,406 in interest, meaning the total cost of your home will effectively be $796,406. In the very first year, your total interest paid is roughly $22,642, while only $3,905 goes toward paying down your principal. By the 15th year, your principal and interest portions balance out, shifting the majority of your payments toward building home equity.
Frequently Asked Questions
Does this calculator include property taxes and insurance?
No, this calculator strictly models your principal and interest (P&I) obligations based on the amortization schedule. You will need to add your local property taxes, homeowner's insurance, and any HOA fees to estimate your full monthly housing expense. For broader tax implications, check our ISO vs NSO Tax Calculator.
Can I deduct the mortgage interest on my 2026 tax return?
Under the current 2026 tax code, you can generally deduct home mortgage interest on the first $750,000 of indebtedness, provided you itemize your deductions rather than taking the standard exemption. Consult IRS Form 1098 and a tax professional for specific advice.
How can I pay off my mortgage faster?
Making extra principal payments each month or a single lump-sum payment annually drastically reduces the lifetime interest of your loan and shortens the amortization timeline, saving you tens of thousands of dollars.
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Disclaimer
Educational and scenario-analysis only; not tax, legal, or investment advice; consult a licensed CPA or financial advisor. Figures reflect 2026 tax statutes and may change.
Built and verified by The Core-AI Engineering Desk — last reviewed August 31, 2026. Calibrated strictly to 2026 statutory figures.