What does 'amortization' actually mean?

It's the process of paying off a loan through fixed payments over time, where each payment covers that period's interest first and puts whatever's left toward the principal balance. The word comes from the same root as 'mortal' — literally, killing off the debt a bit at a time.

Why does the interest and principal split change every payment?

Interest is charged on whatever balance is still outstanding, so early on — when the balance is largest — more of each fixed payment goes to interest. As the balance shrinks, less of the payment is needed for interest, so more goes to principal. The payment amount itself doesn't change; what it buys does.

How much does an extra payment actually save?

It depends on when you make it — an extra payment early in the loan saves more total interest than the same extra payment made near the end, because it removes principal that would otherwise have accrued interest for many more years. Enter an extra monthly payment above to see the exact time and interest saved for your specific loan.

Is this the same as a mortgage calculator?

It works for any fixed-rate installment loan — mortgage, auto, personal, or student loan — not just mortgages. The difference from a typical mortgage calculator is that this one shows the full year-by-year schedule of principal, interest, and remaining balance, not just the monthly payment.

Does this account for property tax, insurance, or PMI?

No — this calculator covers principal and interest only, the actual amortizing part of a loan. For a mortgage payment that includes property tax, insurance, and PMI, use our Mortgage & Loan Calculator instead.

What if my extra payment is too small to make a difference?

Any extra payment that's more than $0 shortens the loan by at least a little, since it goes straight to principal. If the calculator shows no result at all, your base payment plus the extra you entered probably isn't even covering the interest charged each month — increase either number and it'll resolve.

AI Insights

Amortization Calculator

See the full year-by-year payment schedule for any loan — how much goes to principal vs. interest, and how an extra payment shortens the payoff.

Last updated September 4, 2026

Loan amount ($)

Interest rate (% APR)

Loan term (years)

Extra monthly payment (optional)

Monthly payment

$2,212.24

Paid off in 30 yr — around Sep 2056

Total interest paid

$446,406

Total cost of loan

$796,406

Check the exact breakdown of your monthly payment before finalizing your budget, because on a large loan spread over a long term, the vast majority of your initial payments will go toward interest rather than principal. This heavy interest weighting early on means your loan balance decreases very slowly during the first several years. Understanding this initial trajectory helps set realistic expectations for how long it takes to build significant equity.

AI-generated insight

Yearly schedule

Year	Principal paid	Interest paid	Ending balance
1	$3,912	$22,635	$346,088
2	$4,174	$22,373	$341,914
3	$4,454	$22,093	$337,460
4	$4,752	$21,795	$332,709
5	$5,070	$21,477	$327,638
6	$5,410	$21,137	$322,229
7	$5,772	$20,775	$316,457
8	$6,158	$20,388	$310,298
9	$6,571	$19,976	$303,727
10	$7,011	$19,536	$296,716
11	$7,481	$19,066	$289,236
12	$7,982	$18,565	$281,254
13	$8,516	$18,031	$272,738
14	$9,086	$17,460	$263,652
15	$9,695	$16,852	$253,957
16	$10,344	$16,203	$243,613
17	$11,037	$15,510	$232,576
18	$11,776	$14,771	$220,800
19	$12,565	$13,982	$208,235
20	$13,406	$13,141	$194,828
21	$14,304	$12,243	$180,524
22	$15,262	$11,285	$165,262
23	$16,284	$10,263	$148,978
24	$17,375	$9,172	$131,603
25	$18,538	$8,008	$113,065
26	$19,780	$6,767	$93,285
27	$21,105	$5,442	$72,180
28	$22,518	$4,029	$49,662
29	$24,026	$2,521	$25,635
30	$25,635	$912	$0

How to use the amortization calculator

1
Enter the loan amount, interest rate, and term in years.
2
Add an extra monthly payment if you're considering paying more than the minimum.
3
Your monthly payment, total interest, payoff date, and full year-by-year schedule update instantly.

How the schedule works

The monthly payment stays fixed, but the split between interest and principal shifts steadily from mostly interest early on to mostly principal near the end.

Every payment on a fixed-rate loan is the same size, calculated with the standard amortization formula: M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P is the loan amount, r is the monthly interest rate, and n is the number of payments.

Worked example: a $350,000 loan at 6.5% over 30 years. Monthly rate r = 0.065 ÷ 12 = 0.005417, n = 360. The formula gives a payment of $2,212.24/month. In month 1, interest is $350,000 × 0.005417 = $1,895.83, so only $316.40 goes to principal. By year 25, most of that same $2,212.24 payment goes to principal instead.

Because each month's interest is calculated on whatever balance is left, paying down principal faster — through an extra payment — reduces every future month's interest charge too, which is why extra payments save more than their face value in total interest.

Why extra payments matter most early

An extra $200 a month applied in year 1 of a 30-year loan removes principal that would otherwise sit on the books accruing interest for close to three more decades. The same $200 applied in year 28 only prevents two years of interest on that amount — the math still helps, just far less dramatically.

This is also why refinancing resets the clock in a way that can work against you: a refinance restarts the schedule back at mostly-interest payments, even if the new rate is lower. Our Refinance Calculator compares the full picture, not just the new monthly payment.

Everyday uses for an amortization calculator

Checking a lender's numbers: confirming the payment schedule a lender or loan estimate shows you actually matches the loan amount, rate, and term you agreed to.

Deciding whether to pay extra: seeing the exact time and interest an extra monthly payment would save before committing to it long-term.

Any fixed-rate loan, not just mortgages: the same math applies to an auto loan, a personal loan, or a student loan — anywhere payments are fixed and interest accrues on a shrinking balance.

Comparing to a full mortgage payment: if you need property tax, insurance, and PMI included, our Mortgage & Loan Calculator covers the full monthly payment, not just principal and interest.

Juggling multiple debts instead of one loan? Try the Debt Payoff Calculator →

Frequently asked questions

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