Amortization Calculator
See exactly how every payment breaks down — and how much extra payments can save you. Results update instantly.
Loan Details
Current avg 30-yr fixed: 6.4% (Freddie Mac, Apr 2026)
Added to every payment → reduces interest and payoff time
Results
Monthly Payment
$1,876.52
Principal & Interest only
Total Interest
$375,546.38
Total Payments
$675,546.38
💰 Extra Payment Impact
Interest Saved
—
Time Saved
—
Remaining Balance Over Time
Watch your balance decline — slowly at first, then accelerating as more of each payment goes to principal.
Amortization Schedule
| Year | Payment | Principal | Interest | Balance |
|---|
How to Use This Amortization Calculator
Enter your loan amount — the amount you're borrowing, not the purchase price. For a mortgage, that's the home price minus your down payment. Set your annual interest rate and loan term. The Start Date determines when your first payment is due and when the loan pays off.
The most powerful field in this calculator is the Extra Monthly Payment. Even $100–$200 extra per month produces dramatic results — often shaving years off the loan and saving tens of thousands in interest. Enter different amounts to find your sweet spot between payment comfort and interest savings.
Hit Calculate and you'll see your full monthly payment, total interest, payoff date, and the complete year-by-year amortization schedule. Toggle between Yearly and Monthly views depending on how much detail you want.
How Amortization Works
Every fixed-rate loan uses the standard amortization formula: M = P × [r(1+r)^n] ÷ [(1+r)^n − 1], where P is principal, r is the monthly rate, and n is the number of payments. This gives you one fixed monthly payment for the entire loan term.
The payment stays the same every month, but the split between interest and principal changes dramatically. In the first month of a $300,000 loan at 6.4%, you pay $1,600 in interest and only $276 in principal. By year 25, those numbers flip: $276 interest and $1,600 principal. This is why selling or refinancing early costs so much — you've been paying mostly interest.
The Math Behind Extra Payments
Every extra dollar applied to principal reduces your balance immediately. That lower balance means less interest accrues next month — and every month thereafter. This compounding effect makes early extra payments extraordinarily powerful.
On a $300,000 loan at 6.4% for 30 years: adding $200/month extra saves approximately $72,000 in interest and pays off the loan 6 years early. Adding $500/month saves $130,000 and finishes 11 years early. The math is nonlinear — doubling your extra payment more than doubles the savings because each extra payment builds on the previous one.
Example: $300,000 at 6.4%, 30 years
| Extra/mo | Total Interest | Interest Saved | Payoff |
|---|---|---|---|
| $0 | $375,386 | — | Apr 2056 |
| $100 | $319,421 | $55,965 | Jun 2052 |
| $200 | $275,943 | $99,443 | Mar 2050 |
| $500 | $203,041 | $172,345 | Sep 2045 |
Understanding Your Results
Monthly Payment
This is your P&I payment — principal and interest only. Your actual payment to the lender will be higher if your lender collects escrow for property taxes and homeowner's insurance. Those costs don't affect your amortization schedule.
Total Interest
On a 30-year $300,000 mortgage at 6.4%, you'll pay $375,386 in interest — more than the original loan amount. This is the number that motivates most extra payment strategies. Even small additional payments chip away at this figure significantly.
Reading the Schedule
The yearly view shows annual totals: how much you paid, how much went to principal, how much to interest, and your balance at year-end. The monthly view shows every individual payment. Use this to find specific milestones: when your balance drops below $250k, when you hit 20% equity (PMI cancellation trigger), or when your remaining balance equals your annual income.
Frequently Asked Questions
Amortization is the process of paying off debt through regular payments, with each payment split between principal and interest. Understanding amortization helps you see exactly how loans work and find ways to save thousands in interest.
What is loan amortization in simple terms?
Amortization is how each loan payment is split between paying down the principal (the amount you borrowed) and paying interest. In early payments, most of the money goes to interest. In later payments, most goes to principal. Our calculator shows this split for every single payment.
Why do early mortgage payments go mostly to interest?
Interest is calculated on the remaining balance. When the balance is highest (early in the loan), interest is highest. As you pay down principal, the interest portion shrinks. On a $300,000 30-year mortgage at 7%, your first payment is $1,750 interest and $246 principal — the ratio reverses by year 22.
How much do extra payments really save me?
Massively. On a $300,000 mortgage at 7% over 30 years, just $200/month extra payment saves roughly $130,000 in interest and pays off the loan 8 years early. Even $50/month extra makes a meaningful difference over the loan's life.
What's the difference between making one extra payment per year and making bi-weekly payments?
Bi-weekly payments (paying half your monthly payment every 2 weeks) result in 26 half-payments = 13 full payments per year, instead of 12. This effectively adds one extra payment annually, shortening a 30-year mortgage by about 4–5 years.
Can I see how my loan balance decreases each month?
Yes — that's exactly what an amortization schedule shows. Our calculator generates the complete schedule for any loan, showing month-by-month principal paid, interest paid, and remaining balance, plus the total interest savings if you add extra payments.