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Mortgage Amortization Schedule

See every payment — principal, interest, cumulative totals, and remaining balance — month by month over the full life of your loan.

View Year:
Month Payment Principal Interest Cum. Interest Balance Paydown

Results based on user-entered values. For conventional fixed-rate loans only. See Disclaimer.

Understanding Your Amortization Schedule

An amortization schedule shows exactly how each monthly payment on a fixed-rate mortgage is split between principal (what you actually owe) and interest (what the lender charges for the loan). Early in the loan, most of your payment goes toward interest because the balance is highest. As the balance shrinks each month, more of each payment shifts toward principal — that's why the "principal" column grows and the "interest" column shrinks as you move down the table, even though your total monthly payment stays the same.

This front-loaded interest structure is why paying off a mortgage early — even by adding a modest extra amount each month — saves more in total interest than the extra payment itself. Every extra dollar applied to principal reduces the balance the lender charges interest on for every remaining month of the loan.

How the Numbers Are Calculated

The calculator uses the standard fixed-rate amortization formula: monthly interest is your current balance multiplied by the monthly interest rate (annual rate ÷ 12), and principal is the remainder of your fixed payment after that interest is subtracted. Any extra payment you enter is applied directly to principal, which is what shortens the loan term and reduces total interest paid — the "Months Saved" summary card reflects that difference automatically.

Reading the Year-by-Year Summary

Each year in the schedule above is broken out as its own row so you can see the principal-versus-interest split shift over time without scrolling through 360 individual months. Early years are dominated by interest — on a typical 30-year loan starting near 7%, well over half of your first year's payments go toward interest rather than principal. That ratio flips gradually every year as the balance shrinks, until eventually most of each payment is reducing your balance rather than paying the lender. Use the "View Year" filter buttons to jump straight to a specific year instead of scrolling — useful if you're trying to see what your balance will look like in, say, year 7 (a common refinance-consideration point) or year 15 (a common "how much equity do I have" checkpoint).

Extra Payments: Where the Real Savings Come From

Because interest is calculated on your remaining balance every single month, an extra payment applied today keeps compounding in your favor for every month that follows — you're not just skipping one month's interest, you're permanently lowering the balance interest gets charged on for the rest of the loan. That's why the "Months Saved" figure often looks disproportionately large compared to the extra amount: on a $320,000 loan at 7%, an extra $200/month can cut several years off a 30-year term and save tens of thousands in interest, even though the extra payments themselves only add up to a fraction of that. If you're deciding between paying extra on your mortgage or investing that money elsewhere, the guaranteed "return" of an extra mortgage payment is effectively your interest rate — compare that to what you'd realistically expect from the alternative before deciding.

Refinancing and Selling: How This Schedule Helps You Decide

Two of the most common reasons people pull up an amortization schedule are to check how much equity they've built before selling, and to see exactly how many years of interest payments they'd be "restarting" if they refinanced. Both questions come straight out of the "Balance" column: subtract the balance at any given month from your original home value (adjusted for any appreciation) to estimate equity, or compare your current balance and remaining months against a hypothetical new 30-year loan to see the term-extension effect that our refinance calculator analyzes directly. If a refinance is on your radar, run the numbers on both calculators together — this schedule shows you exactly where you are today, and the refinance calculator shows what changes from here.

What This Schedule Assumes

This calculator assumes a single, unchanging fixed interest rate for the full loan term, a consistent extra payment amount every month (rather than occasional lump sums), and no missed or late payments. It does not model adjustable-rate mortgages, balloon payments, biweekly payment schedules, or prepayment penalties. It also covers principal and interest only — property taxes, homeowners insurance, PMI, and HOA dues are not included in the schedule, since those are typically collected in a separate escrow account and don't reduce your loan balance. For your complete monthly obligation including those items, use our PITI calculator.

Frequently Asked Questions

Why does my interest payment go down over time if my rate never changes?
Your interest rate stays fixed, but interest is calculated on your remaining balance each month — not the original loan amount. As you pay down principal, the balance shrinks, so the dollar amount of interest charged each month shrinks with it, even though the rate itself never moves.
Does a small extra payment really make a difference?
Yes — because mortgage interest compounds on the remaining balance, even $100-200 extra per month can shave years off a 30-year loan and save tens of thousands in total interest. Try entering different extra-payment amounts in the calculator above to see the effect on your own numbers.
When do I start building equity faster?
Roughly around the midpoint of a standard 30-year loan, the principal-to-interest ratio flips and more of each payment starts going toward your balance than toward the lender. Extra payments made earlier in the loan accelerate that crossover point significantly.
Does this calculator account for property tax and insurance escrow?
No — this schedule covers principal and interest only, which is the portion that actually amortizes. Property tax, homeowner's insurance, and PMI (if applicable) are typically collected separately in an escrow account and don't reduce your loan balance. Use our PITI calculator for a full monthly payment estimate.
Can I export this schedule to check my own math or share it with a lender?
Yes — use the "Export CSV" button above the table to download the full month-by-month schedule as a spreadsheet file, which opens in Excel, Google Sheets, or Numbers. This is useful for double-checking a lender's own amortization schedule against an independent calculation, or for your own records when comparing loan offers.
Why does my lender's schedule show a slightly different total than this one?
Small differences (usually a few dollars over the life of the loan) typically come from rounding conventions or the exact day-count method a servicer uses. Larger differences usually mean the lender's schedule includes escrowed items (taxes, insurance, PMI) that this principal-and-interest-only calculator doesn't, or reflects a rate or term that differs slightly from what you entered here. Your official amortization schedule from your loan servicer is always the authoritative one.
Methodology & sources: This schedule is generated from the standard fixed-rate mortgage amortization formula applied to the home price, down payment, rate, term, and extra payment you enter — the same underlying math used by our refinance calculator. It does not use or estimate today's actual market mortgage rates; enter your own quoted or assumed rate. Content reviewed for accuracy August 13, 2026. Spotted an error or have a question? Contact us.