What is mortgage amortization?

Mortgage amortization is the process of paying off a loan through regular monthly payments over a set period. Each payment is split between principal (reducing the loan balance) and interest (the cost of borrowing). Early payments are mostly interest, gradually shifting toward principal over time.

How much interest will I pay over 30 years?

Total interest depends on your loan amount and rate. For example, a $300,000 loan at 6.5% over 30 years results in approximately $382,000 in total interest, meaning you pay more than double the original loan amount.

Do extra payments reduce my mortgage term?

Yes, extra payments go directly to principal, reducing your balance faster. Even an extra $100 per month on a 30-year mortgage can shorten the loan by 4-5 years and save tens of thousands in interest.

What is the difference between amortization and simple interest?

Amortization spreads payments evenly over the loan term with a fixed schedule. Simple interest is calculated only on the outstanding principal. Most mortgages use amortization, where early payments are interest-heavy and gradually shift toward principal.

Amortization Schedule: See Your Payment Breakdown Over Time

View a month-by-month breakdown of your mortgage payments showing exactly how much goes to principal vs. interest over the life of your loan. Download your full schedule as CSV.

Mortgage Amortization Calculator

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Loan amount Interest rate (APR %) Loan term (years) Start dateUsed for schedule dates Home value (optional, for equity)Equity = home value − remaining balance

Extra payments (applied to principal)

Extra monthly Extra annualApplied once per year One-time extra One-time month #e.g., 12 = after 12 payments

Monthly P&I payment

$0.00

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Total interest (base)

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No extra payments.

Total interest (with extras)

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Time saved

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How much the loan term shrinks.

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Years Months

Amortization Schedule—

#	Date	Payment	Extra	Principal	Interest	Balance	Equity

Estimates only. Exact amortization may vary by lender rounding rules.

What Is an Amortization Schedule?

An amortization schedule is a complete table showing every monthly mortgage payment broken down into principal and interest components. Early in the loan, most of your payment goes toward interest. Over time, the balance shifts — more goes to principal and less to interest. Understanding this schedule helps you see how equity builds and how extra payments can save you thousands.

Key Concepts

Principal Portion

The part of each payment that reduces your loan balance. This increases each month as the interest portion decreases.

Interest Portion

The cost of borrowing, calculated on the remaining balance. This decreases each month as you pay down the principal.

Remaining Balance

Your outstanding loan amount after each payment. Watching this decrease is one of the most satisfying parts of homeownership.

Total Interest Paid

The cumulative interest over the life of the loan. On a $300,000 30-year loan at 6.5%, you would pay about $382,000 in total interest.

Extra Payments

Even small additional monthly payments dramatically reduce total interest and shorten the loan term. An extra $100/month on a 30-year loan can save years.

How to Use This Calculator

Enter Your Loan Details

Loan Amount: The total amount you are borrowing (home price minus down payment).
Interest Rate: Your annual interest rate (APR). Check today's rates.
Loan Term: Choose 15-year or 30-year fixed (or enter a custom term).
Extra Monthly Payment (optional): Any additional amount you plan to pay each month toward principal.
Start Date: When your first payment begins (for date-labeled schedules).

The Math Behind Amortization

Each month, your lender calculates interest on the remaining balance: Monthly Interest = Balance x (Annual Rate / 12). The rest of your fixed payment goes to principal. As the balance decreases, less goes to interest and more to principal — this is why the first years feel slow for equity building, but it accelerates over time.

Monthly Interest = Remaining Balance x (APR / 12)

Why Extra Payments Matter

Making one extra mortgage payment per year on a 30-year loan can shorten it by about 4–5 years. Bi-weekly payment plans accomplish a similar result by making 26 half-payments (equivalent to 13 full payments) per year instead of 12. Use the amortization schedule to see the exact impact of extra payments on your specific loan.

Ready to explore your options? Use our mortgage calculator to estimate your monthly payment, or check refinance options if you already have a mortgage.