Mortgage Amortization Calculator

Every fixed-rate mortgage follows a schedule written the day you sign: early payments are mostly interest, later ones mostly principal. Enter your loan details to see the whole curve and a year-by-year table.

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Calculator

Your results

Monthly P&I$2,022.62
Loan amount$320,000
Total interest over the loan$408,142
Payoff time30 yrs

Charts & visualization

Amortization schedule

Balance remaining after each year of payments.

Every chart’s underlying numbers are available as text — use the “view as table” control under each chart.

Amortization schedule table

Yearly amortization summary
YearPrincipal paidInterest paidRemaining balance
1$3,577$20,695$316,423
2$3,816$20,455$312,607
3$4,072$20,200$308,535
4$4,345$19,927$304,191
5$4,636$19,636$299,555
6$4,946$19,325$294,609
7$5,277$18,994$289,332
8$5,631$18,641$283,701
9$6,008$18,264$277,694
10$6,410$17,861$271,284
11$6,839$17,432$264,444
12$7,297$16,974$257,147
13$7,786$16,485$249,361
14$8,308$15,964$241,053
15$8,864$15,407$232,189
16$9,458$14,814$222,732
17$10,091$14,180$212,641
18$10,767$13,505$201,874
19$11,488$12,784$190,386
20$12,257$12,014$178,129
21$13,078$11,193$165,051
22$13,954$10,317$151,097
23$14,888$9,383$136,208
24$15,886$8,386$120,323
25$16,949$7,322$103,373
26$18,085$6,187$85,289
27$19,296$4,976$65,993
28$20,588$3,683$45,405
29$21,967$2,305$23,438
30$23,438$833$0

Table updates live as you change inputs.

How it works

The calculator builds a month-by-month ledger. Each month, interest equals the current balance multiplied by the monthly rate; whatever remains of the fixed payment reduces principal. As the balance falls, the interest slice shrinks and the principal slice grows — that dynamic is amortization.

The chart shows the declining balance year by year, and the table beneath it aggregates each year of payments so you can see how much of your money went to interest versus equity at every stage of the loan.

Formula used

Interest(m) = Balance(m) × r · Principal(m) = Payment − Interest(m) · Balance(m+1) = Balance(m) − Principal(m)
  • r — monthly rate = APR ÷ 12 ÷ 100
  • Payment — fixed amount from the standard amortizing formula
  • Repeats — every month until the balance reaches zero

Example calculation

A $320,000 loan at 6.5% for 30 years carries a fixed payment of $2,023. In year one, roughly $20,695 of your $24,271 in payments goes to interest — about 85.3% of every dollar. By year twenty the split has flipped and most of each payment builds equity. Total interest across all 360 payments comes to $408,142 — more than the original loan itself.

Assumptions & limitations

  • Fixed rate for the entire term; ARMs re-amortize after each adjustment period.
  • No extra payments, prepayment penalties, or missed payments modeled here.
  • Taxes and insurance excluded to isolate the loan itself.
  • Yearly figures aggregate twelve exact monthly computations — no approximations.

Results are planning estimates based on your inputs and the stated assumptions — not financial advice or a loan offer. Verify important figures with your lender or advisor.

Frequently asked questions

What does amortization mean?

It is the process of retiring a loan with fixed payments over time. Because interest is charged on the outstanding balance, the interest portion is largest at the start and shrinks as principal is repaid.

Why is so much of my early payment interest?

Interest is proportional to what you still owe. Early on the balance is near its peak, so interest consumes most of each payment. Around the midpoint of a 30-year loan, principal finally overtakes interest.

How do I see the effect of extra payments?

Use the Extra Mortgage Payment Calculator, which runs two schedules side by side and quantifies months and interest saved.

Do extra payments change my required payment?

No — the required monthly payment stays the same. Extra amounts retire the balance sooner, shortening the schedule and cutting total interest.

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