Mortgage Amortization Schedule: How to Read Every Row

A full schedule for a 30-year loan has 360 rows. Printing all of them here would bury the pattern, so this table keeps the rows where something interesting happens. Every figure comes from the same month-by-month calculation the calculator on this page runs.

Three things jump out. First, the payment never changes — $2,215.62 in row 1 and in row 360 — but its split changes every single month. Second, the first payment sends $1,973.33 to the lender as interest and only $242.28 toward the house; across the whole first year, 88.7% of what you pay is interest. Third, by the last row you have paid $477,622 in interest on a $320,000 loan. None of that is a lender trick. It is simply what happens when interest is charged each month on whatever balance is left.

The arithmetic for any row is short. Take the balance after the previous payment, multiply by the monthly rate (7.40% ÷ 12 = 0.6167%), and that is the interest portion. Subtract it from the fixed payment and the remainder is principal. Subtract the principal from the balance and you have the next row's starting point. Row 1: $320,000 × 0.006167 = $1,973.33 interest, $2,215.62 − $1,973.33 = $242.28 principal, $320,000 − $242.28 = $319,757.72. The full derivation of the payment itself is on our how mortgage amortization is calculated guide and the mortgage amortization formula page.

Lenders, servicers, spreadsheets and calculators label the columns differently, but they always carry the same five pieces of information:

• Payment number or date. Month 1 is usually the first full month after closing. Your first payment date is on your closing disclosure, not month one of the calendar year.
• Interest. The cost of borrowing that month, computed on the balance outstanding before the payment. It shrinks every month because the balance does.
• Principal. The part of the payment that reduces what you owe. It grows by a little each month — from $242.28 to $243.78 to $245.28 in the table above — because each month's interest bill is slightly smaller.
• Remaining balance. What you would owe if you paid the loan off that day, before any per-diem interest or fees your servicer adds to a payoff quote.
• Cumulative interest. Not every schedule shows it, but it is the column that makes the true cost of a long term obvious.

What the schedule does not show is just as important. A standard amortization schedule covers principal and interest only. Most homeowners actually send their servicer a larger amount, because property taxes and homeowners insurance are collected alongside the loan payment and held in an escrow account. The Consumer Financial Protection Bureau explains the difference between the principal-and-interest payment and the total monthly payment, and how an escrow account works. Escrow amounts change when your tax bill or premium changes; the amortization schedule does not. If you want both on one page, use our amortization with taxes and insurance calculator or the mortgage calculator with PMI, taxes and insurance.

The schedule also assumes a fixed rate and on-time payments of exactly the scheduled amount. An adjustable-rate loan gets a new schedule each time the rate resets, and a late payment, a skipped payment under forbearance, or an extra payment all make the printed schedule out of date from that month on.

Scrolling a 360-row table is tedious, but three rows are worth finding on your own loan.

1. The crossover month. This is the first payment in which more goes to principal than to interest. On the $320,000 example it is payment 249 — year 21. Before it, you are mostly renting money; after it, you are mostly buying the house. Higher rates push the crossover later, which is why borrowers who locked in at 3% saw it a decade earlier than today's borrowers will.

2. The halfway balance. Owing half the original amount sounds like it should happen at the halfway point of the term. It does not. The balance first falls below $160,000 at payment 265, roughly 22 years in. Anyone who plans to sell or refinance within ten years should know that after 120 payments this loan still has $277,129 outstanding — 87% of where it started.

3. The year-by-year turn. Grouping the schedule into years makes the shift easier to see:

The yearly interest figure matters at tax time. Your servicer reports the interest you paid during the calendar year on Form 1098 — the IRS requires lenders to issue it when they received $600 or more of mortgage interest from you — and whether that interest is deductible depends on the rules in IRS Publication 936 and on whether you itemize. Your 1098 and your schedule's yearly interest should agree closely; a large gap usually means a payment was applied late or an escrow item was mislabeled.

Because interest is charged on the remaining balance, any extra principal you pay changes every row that follows it. Add $200 a month to the $320,000 example, applied to principal from the first payment, and the schedule shrinks from 360 rows to 277 — the loan is gone in 23 years and one month instead of 30. Total interest falls from $477,622 to $347,099, a saving of $130,523 for roughly $55,000 of extra payments made along the way.

A few practical points decide whether that saving actually shows up on your statement:

1. Tell the servicer it is principal. Extra money sent without instructions can be held as a future payment rather than applied to the balance. Fannie Mae's Selling Guide describes how principal curtailments are handled on loans it buys.
2. Check for a prepayment penalty. Most conventional loans today have none, but the CFPB explains when a prepayment penalty can apply. It will be on your closing disclosure.
3. Your required payment does not drop. Prepaying shortens the schedule; it does not lower the monthly amount. Lowering the payment requires a recast — compare the two with our mortgage recast calculator.
4. Earlier beats bigger. $200 in month 1 removes interest for 359 future months; the same $200 in month 300 removes it for 60. That is why the schedule above rewards extra payments most in the years when principal is smallest.

To see your own version, set an extra monthly amount or a one-time lump sum in the calculator above; the schedule and chart redraw instantly. For a deeper look at strategies, see the amortization schedule with extra payments guide or the biweekly mortgage payment calculator.

You have three reliable ways to produce a schedule that matches your loan to the penny, and one rule for checking it.

Ask your servicer. Many servicers show an amortization table in the online account; others will send one on request. Federal rules require your servicer to apply full payments as of the day they arrive and, in most cases, send a statement each billing cycle showing how each payment was applied — the CFPB summarises what servicers must do.

Use the calculator on this page. Enter the original loan amount, the note rate and the term from your closing documents. The schedule it builds can be downloaded as a CSV and opened in any spreadsheet. If you are part-way through the loan, enter today's balance and the remaining years instead of the original numbers.

Build it in a spreadsheet. Excel and Google Sheets both have a PMT function that returns the fixed payment; Microsoft documents how PMT works. From there each row is the three-line calculation shown in the first section. Our mortgage amortization calculator for Excel page walks through the formulas.

The check: take your most recent statement's principal balance and find it in your schedule. If the schedule says you should owe noticeably less, either an extra payment was not applied to principal or a payment was posted late. Raise it with the servicer in writing.

How this page was put together

I generated every figure on this page with the amortization routine that powers this site's calculators, using a $320,000 principal, 360 monthly payments and the 7.40% average 30-year rate from Freddie Mac's Primary Mortgage Market Survey for the week of October 8, 2026 (read October 12, 2026). I then summed the schedule to confirm that the 360 principal payments add back to exactly $320,000 and that cumulative interest matches the payment total minus principal. The rate is an average; your own quote may be higher or lower, which is why the calculator takes your inputs rather than ours. Start from the mortgage amortization calculator homepage for the full tool with PMI, taxes and biweekly options.