Mortgage Rate Calculator with Amortization: How Your Rate Reshapes the Schedule

On a fixed-rate loan the first month's interest is simply the balance times one-twelfth of the annual rate. At 7.40% that is $350,000 × 0.074 ÷ 12 = $2,158.33. The payment is $2,423.33, so only $265.00 of payment one reduces the loan. That split is the starting point of the whole schedule, and it is set almost entirely by the rate.

Inputs: $350,000 loan, 30-year fixed, monthly payments, no extra principal. Computed with this site's amortization formula on 2026-10-19.

Three things stand out in this grid.

The interest share climbs fast and then flattens. Going from 5.50% to 7.40% pushes the interest share of the first payment from 80.7% to 89.1%. Put the other way, the principal you retire in month one falls from $383.09 to $265.00, a drop of almost a third, while the payment itself rises by only $436. Higher rates do not just cost more; they also slow the rate at which you own the house.

The crossover month moves by years, not months. The crossover is the first payment in which more goes to principal than to interest. At 5.50% it arrives at payment 210, about 17½ years in. At 7.40% it is payment 249, more than 20 years in: at that point the split is $1,206.08 of interest and $1,217.25 of principal, with $194,363 still owed. At 8.50% it slips to payment 263. Each half-point of rate in this range pushes the crossover back by 6 to 13 payments. Notice that the crossover month does not depend on the loan amount at all, only on the rate and term, so the column holds for a $200,000 or a $700,000 loan alike. A shorter term changes it dramatically: on a 15-year loan at the 6.71% weekly average, principal overtakes interest at payment 57, under five years in.

Lifetime interest is the rate's biggest lever. On this loan the difference between last October's 6.27% average and this October's 7.40% is $263.77 a month, which feels modest, and $94,956 over the full term, which does not. Year one alone shows it: at 7.40% you pay $25,790 of interest and reduce the balance by $3,290; at 6.27% you would have paid $21,829 of interest and repaid $4,086.

If you want to see exactly how each payment is split row by row, our guide to how mortgage amortization is calculated works through the arithmetic, and the principal and interest calculator isolates that split for any single month.

Any mortgage rate calculator with amortization should show you this table for your own loan, because most mortgages end long before payment 360, through a sale or a refinance, so the balance a few years out is often a more practical number than lifetime interest. Here the rate works in two directions at once: a higher rate means a bigger payment and a bigger balance remaining after the same number of payments.

Inputs: Same $350,000, 30-year fixed loan; balances after payment 60 and payment 120. Computed with this site's amortization formula on 2026-10-19.

After five years at 7.40% you have paid $145,400 in total and still owe $330,830; only $19,170 of that money, about 13%, went to the loan. At 5.50% the same five years retire $26,388. The gap of $7,218 in equity is money that would otherwise come back to you at the closing table when you sell, which is why a quoted rate deserves the same attention as a quoted price.

The ten-year column matters for refinancing. If you take a loan at 7.40% today and refinance in a few years, the new loan starts from the higher balance in this table, not from the original $350,000, and the new schedule begins again at the interest-heavy front end. Before you assume a later refinance will "fix" today's rate, run both loans in the refinance amortization calculator, which carries the remaining balance across and counts closing costs.

A shorter term changes the picture more than any realistic rate move. On a 15-year loan at the 6.71% weekly average, the payment is $3,089.43, and the balance after five years is $269,538, after ten $157,105, with total interest of $206,097. That is less than the interest a 30-year loan at 7.40% charges in its first ten years. Our 15 year vs 30 year mortgage calculator lines the two schedules up side by side.

There is also a middle route that keeps the 30-year payment as a floor. Extra principal paid early in the schedule does the most work, precisely because the interest share is highest then; the mortgage calculator with extra payments shows how many payments a fixed monthly addition removes at your rate. And if you want every row printed, the 30-year mortgage amortization schedule lists all 360.

The rate that drives an amortization schedule is the note rate, the interest rate written in your loan documents. It is the number you should enter in the calculator. The APR is a different, broader number. The Consumer Financial Protection Bureau's explanation of interest rate versus APR (read October 2026) defines the interest rate as the yearly cost of borrowing that "does not reflect fees or any other charges," and the APR as a broader measure that "reflects the interest rate, any points, mortgage broker fees, and other charges that you pay to get the loan," which is why the APR is usually higher. On a Loan Estimate, the CFPB notes, the interest rate is on page 1 under "Loan Terms" and the APR is on page 3 under "Comparisons."

Why not amortize at the APR? Because no payment is ever calculated from it. Your servicer charges interest on the balance at the note rate every month; the fees behind the APR are paid at closing (or financed) and never show up as a row in the schedule. Entering the APR in an amortization calculator overstates the monthly payment and every interest figure that follows.

To see how the two numbers relate, the table below takes the $350,000 loan at a 7.40% note rate and adds different amounts of up-front charges. The fee amounts are illustrations, not typical figures; your own are itemized on the Loan Estimate.

Inputs: $350,000 loan at a 7.40% note rate, 30 years; APR solved as the rate that equates the payment stream to the loan amount less the charges. Computed with this site's amortization formula on 2026-10-19.

Each 1% of the loan paid in charges lifts this APR by roughly a tenth of a point, because the charges are spread over a 30-year payment stream. The reverse is also true: a loan whose APR sits close to its note rate is carrying few up-front charges. That makes the gap between the two a quick screen when you compare offers, but the CFPB cautions against looking at the APR alone, and specifically warns that for adjustable-rate loans the APR does not reflect the maximum rate the loan can reach. The APR also assumes you keep the loan for its full term; if you expect to sell or refinance early, the up-front charges are spread over fewer years and cost you more per year than the APR suggests. When the schedule is the question, use the note rate; when you are comparing what two lenders charge, use the APR as one input among several.

Discount points are the main way to pay for a lower note rate. According to the CFPB's guide to points and lender credits (read October 2026), one point equals one percent of the loan amount, points are paid at closing, and they appear on page 2, Section A of the Loan Estimate and Closing Disclosure. The CFPB is explicit that how much a point lowers the rate "depends on the specific lender, the kind of loan, and the overall mortgage market," so there is no standard reduction to plug in. The only reliable inputs are the rate-and-points options a lender quotes you in writing.

To show the method, suppose a lender quotes 7.40% with no points, 7.15% for one point and 6.90% for two. Those three rates are invented for the illustration; substitute your own.

Inputs: $350,000, 30-year fixed. The rate offered for each point is a hypothetical input, not a market figure. Computed with this site's amortization formula on 2026-10-19.

There are two ways to measure the break-even, and the difference matters.

• Payment-only break-even: points cost ÷ monthly saving. $3,500 ÷ $59.41 = about 59 months. This is the figure most lenders quote.
• Schedule-aware break-even: the lower rate also means more of each payment goes to principal, so the balance falls faster. Adding that balance gap to the payment savings, the one-point loan has repaid its $3,500 by payment 48, about a year sooner. After five years the borrower is $912 ahead; after ten, $5,344; held to term, $17,886 (two points: $1,818, $10,664 and $35,562).

Neither measure counts what the $3,500 could have earned elsewhere, or what else it could have done at closing, such as a larger down payment. The CFPB's own advice is the practical test: ask the lender to show you options with and without points, and compare total costs over the shortest, longest and most likely time you expect to keep the loan. If you are unsure whether you will stay past the break-even month, the CFPB suggests you might not want to pay points at all. Points are also gone if you refinance, which is why the break-even should be compared with your expected holding period, not with the 30-year term.

The same logic runs in reverse for lender credits, which reduce closing costs in exchange for a higher rate: the credit is worth taking if you expect to leave the loan before the higher payments add up to more than the credit. Run each quoted rate through the mortgage rate calculator with amortization above, note the balance at the year you expect to move, and the right choice usually becomes obvious. For a refresher on how the schedule itself is built, the mortgage amortization formula page has the algebra, and the mortgage amortization calculator homepage adds taxes, insurance and PMI to the same schedule.