How much of your mortgage payment is interest?

Mortgage rates are still high by recent standards. Freddie Mac's weekly national average was 7.32% for a 30-year loan on October 22, 2026, down from 7.40% on October 8, while the 15-year average moved from 6.73% to 6.68%, according to the Primary Mortgage Market Survey. These are weekly national averages that move, so check the latest survey before using them. At rates near 7%, the interest share of each payment is what surprises most buyers.

This guide follows one loan from the first payment to the crossover point where principal takes over. Take a fictional example: a buyer, Maya (fictional), buys a 400,000 dollar home with 80,000 dollars down, leaving a 320,000 dollar loan at 7% fixed over 30 years. The monthly principal and interest payment is 2,128.97 dollars. Every figure below comes from that loan's amortization schedule, which you can reproduce with our mortgage calculator.

What does mortgage amortization mean?

Amortization means paying a loan down in equal installments that cover both interest and principal. Each month, interest is charged on the remaining balance, and whatever is left of your fixed payment reduces the balance. Because the balance is largest at the start, the interest charge is largest then too, so early payments go mostly to interest even though the payment never changes.

That fixed payment is not a guess. It is the amount that, paid every month for 360 months, clears exactly 320,000 dollars of principal plus all the interest charged along the way. As the balance falls, the interest slice shrinks and the principal slice grows by the same amount. The payment stays 2,128.97 dollars throughout, but what it buys shifts every single month.

Watch the very first payment to see the mechanism up close. In month one the balance is the full 320,000 dollars, so interest is 320,000 times 7% divided by 12, which is 1,866.67 dollars. Of the 2,128.97 dollar payment, only 262.30 dollars reduces the loan, leaving a balance of 319,737.70 dollars. In month two the interest charge is a touch smaller, about 1,865.14 dollars, so about 263.83 dollars goes to principal. Every month repeats this pattern: a slightly smaller interest charge frees a slightly larger principal slice.

How much of each early payment is interest?

In year one, Maya (fictional) pays about 25,548 dollars across 12 payments, and 22,297 dollars of that, about 87%, is interest. Only 3,251 dollars reduces the loan. After five full years she has paid about 127,738 dollars, yet the balance has fallen by only 18,779 dollars, from 320,000 to 301,221. That slow start is normal, not a sign of a bad loan.

Two things are worth noticing. First, the shift is gradual: by year 5 the principal share has grown from 13% to 17% of each year's payments, which still feels slow. Second, the total cost is large because the balance stays high for so long: over the full 30 years this loan collects 446,428 dollars of interest, about 1.4 times the amount borrowed. That total is why small extra payments, covered below, have such outsized effects.

When does principal overtake interest?

On this 7% loan, principal first exceeds interest in year 21. That year the schedule shows about 13,128 dollars of principal against 12,419 dollars of interest, and from year 22 on the principal slice stays larger. Everything before that point is interest-majority territory, which is why the balance still sits above 183,000 dollars after two decades of on-time payments.

The rate decides where that crossing lands. At 4% on the same 320,000 dollar loan over 30 years, the crossover arrives in year 14 instead of year 21, and the first year looks very different: 12,697 dollars of interest against 5,635 dollars of principal. A lower rate means less interest accrues on each dollar of balance, so the fixed payment eats into principal from the start. If you are weighing loan lengths rather than rates, see our comparison of the 15-year against the 30-year mortgage, which reruns these numbers for a shorter term.

What does one extra payment a year change?

Add one full extra payment a year, applied to principal, and the same 7% loan ends about 75 months early and collects about 109,253 dollars less interest. One extra payment equals one twelfth more each month, roughly 177 dollars on top of the 2,128.97 dollar payment, which is why this trick is often described as paying a little extra monthly.

The saving comes from compounding in reverse. Every extra dollar cuts the balance that next month's interest is charged on, so each later payment contains a little more principal, which cuts the balance faster again. The effect is strongest early, when the balance is highest, so starting the habit in year one beats starting it in year ten. Before committing, check that your lender applies extra amounts to principal without a prepayment fee, and keep the payment affordable alongside the rest of your budget.

Compare two fictional borrowers to feel the gap. Maya (fictional) pays the scheduled 2,128.97 dollars and nothing more, so she pays for the full 30 years and 446,428 dollars of interest in total. Her twin brother, Daniel (fictional), takes the same loan on the same day but adds one extra full payment a year from the start. Daniel finishes about 75 months early and pays about 109,253 dollars less interest, while his monthly budget looks almost identical: roughly 177 dollars extra a month. The lesson is that a small, steady addition beats an occasional large one, because money added early skips interest charges for every remaining month of the loan.

How do you read your lender statement against the schedule?

Your statement and the schedule show the same loan from two angles. The schedule predicts each year's interest, principal, and balance in advance. The statement reports what actually happened: interest paid so far this year, principal repaid, the current balance, and often an escrow section for property tax and insurance. Work through it in four steps.

1. Find your loan year. Count from your first payment date, not the calendar year. If Maya's (fictional) first payment was March 2025, then March 2026 starts her loan year two, and that is the schedule row to check against.
2. Compare year-to-date interest. Add the interest portions of the payments you have made this loan year and check the sum against the schedule row. In Maya's (fictional) loan year one the running total after six payments should sit near 11,177 dollars. Small gaps usually come from payment timing, while a large one deserves a call to the servicer.
3. Check the balance, not only the payment. Confirm the statement balance matches the schedule's path after your payments. Extra principal payments should show up as a balance below the scheduled line, which is how you verify they were applied to principal rather than held as future payments.
4. Separate escrow from the loan. Tax and insurance pass through a separate escrow account and never reduce the balance, so do not expect them in the interest and principal columns. If the total withdrawal changed, look at the escrow analysis first, since tax reassessments move that part most often.

Two common confusions are worth clearing up. First, escrow is not part of amortization: tax and insurance pass through a separate account and never reduce the loan, so your total monthly withdrawal is higher than the 2,128.97 dollars of principal and interest. Second, slow early equity is exactly why buying takes time to beat renting, as our rent vs buy break-even year guide shows: run your own horizon in the rent vs buy calculator before deciding a purchase is an investment win. In Nethaven, you can track the mortgage as a loan account with its balance and payoff progress visible next to your net worth (see debt and goals), which makes that slow early progress easier to watch without logging into the servicer.