Mortgage Amortization Calculator

Use this mortgage amortization calculator to see your monthly payment and a full amortization schedule for any fixed-rate loan. Enter your loan amount, interest rate, and loan term. The calculator breaks every payment into principal and interest so you know exactly where your money goes, from the first month to the last.

This tool generates an estimated amortization schedule in seconds. No signup. No credit check. Using this calculator will never affect your credit score.

How the Mortgage Amortization Calculator Works

Enter four inputs and get a complete payment breakdown:

• Loan amount: the total you plan to borrow (or your current loan balance if you are modeling a current mortgage).
• Interest rate: the annual rate on the loan. This is the note rate, not the APR. APR includes fees and costs the calculator does not factor in.
• Loan term: how many years you have to repay, such as 15 or 30 years.
• Extra payment (optional): any additional amount you want to add each month.

Hit calculate, and the tool returns your estimated monthly payment plus a detailed amortization schedule showing every single payment over the life of the loan. You can see how much of each payment goes toward interest and how much goes toward the principal.

Use the Mortgage Calculator for a New Mortgage or Mortgage Loan

Considering a new mortgage? This mortgage calculator helps you estimate costs before you commit.

You can use it to compare a 15-year loan against a 30-year mortgage. You can test different interest rates to see how they change your monthly mortgage payment. You can also plug in different down payment scenarios by adjusting the loan amount.

Already have a mortgage loan? Enter your current loan balance, remaining term, and rate to generate an estimated amortization schedule for what you still owe. This is helpful when you are thinking about refinancing or when you want to plan extra payments on your current mortgage.

How Amortization Works for a Fixed-Rate Loan

Amortization is the process of repaying a loan through scheduled payments over a set period. Each payment is the same dollar amount, but how that payment is allocated changes every month.

In the early years, most of your monthly payment goes toward interest. Only a small portion goes toward reducing the principal. As your loan balance shrinks, less interest accrues each month, so more of each payment goes toward the principal.

By the final years of a 30-year mortgage, nearly every dollar of your payment goes toward principal. This gradual shift is what an amortization schedule shows you, payment by payment.

The Amortization Formula Behind Your Monthly Payment

The standard amortization formula for a fixed-rate loan is:

M = P × [r(1 + r)^n] / [(1 + r)^n − 1]

Where:

• M = monthly principal and interest payment
• P = loan amount (the starting balance)
• r = monthly interest rate (annual rate divided by 12)
• n = total number of payments (loan term in years × 12)

For example, a $300,000 loan at 6.5% for 30 years works out to r = 0.005417 and n = 360. The formula produces a monthly payment of about $1,896.

This calculator uses the same amortization formula. You do not need to calculate amortization by hand. But understanding the math helps you see why small rate changes have such a large effect over the life of the loan.

How do I build an amortization schedule by hand? Multiply your current balance by the monthly rate to get that month's interest. Subtract interest from your fixed payment to get the principal portion. Subtract the principal from the balance. Repeat for every remaining month. It is tedious, which is exactly why this calculator exists.

Your Amortization Schedule Payment by Payment

An amortization schedule is a table listing every periodic payment from month one through the final payoff. Each row shows:

1. Payment number
2. Payment amount
3. Interest portion
4. Principal portion
5. Remaining loan balance

This amortization table lets you look up any specific month and see exactly where that payment goes. For a 30-year mortgage, the schedule contains 360 rows. For a 15-year loan, 180 rows.

How does the loan term affect my amortization schedule? A shorter term means higher monthly payments but dramatically less total interest. A 15-year loan on $300,000 at 6.5% costs roughly $2,613 per month, about $717 more than the 30-year option. But you save over $180,000 in total interest and own your home in half the time.

The full amortization schedule the calculator generates lets you compare these scenarios side by side.

Where Each Payment Goes: Principal, Interest, and Loan Amount

Every monthly payment you make covers two things: the interest owed that month and a portion that reduces your loan balance.

Month 1 example (on a $300,000 loan at 6.5%): your payment is about $1,896. The interest portion is $1,625. The principal portion is only $271. That means roughly 86% of your first payment covers the interest.

Month 180 (halfway through a 30-year term): interest drops to about $1,025, and principal rises to $871. The crossover point, where more of each payment goes toward principal than interest, happens around year 18 on a typical 30-year mortgage at this rate.

Understanding where each payment goes toward the principal versus interest helps you make informed decisions about extra payments and refinancing.

Making Extra Payments to Repay Your Mortgage Faster

Paying extra on your mortgage is one of the simplest ways to reduce total interest and pay off your loan ahead of schedule. Even a small additional payment each month can shave years off a 30-year mortgage.

Extra payments go directly toward reducing your loan balance. A lower balance means less interest accrues the following month, which accelerates the payoff cycle.

What is the effect of paying extra principal on your mortgage? Every extra dollar reduces your loan balance immediately, which reduces the interest charged on every future payment. The savings compound over time.

How Extra Payment Amounts Change Your Amortization Schedule

The calculator lets you enter an extra payment amount and instantly see how it changes your amortization schedule. Here is what different extra payments do on a $300,000 loan at 6.5% for 30 years:

These are estimates. Your exact savings depend on your specific rate, balance, and when you start.

How many years will come off my mortgage by paying extra? That depends on the amount and how consistently you pay. Use the calculator to test different scenarios with your own numbers.

Common Amortization Strategies With Extra Payments

Several approaches can help you repay your mortgage faster:

• Fixed monthly extra: add a set amount, like $100 or $200, to every payment. Consistent and easy to budget.
• One extra payment per year: make 13 payments instead of 12. Many people use a tax refund or bonus for this. One extra payment per year on a 30-year mortgage typically cuts about 4 years off the loan.
• Biweekly payments: pay half your monthly amount every two weeks. Because there are 26 biweekly periods in a year, you end up making the equivalent of 13 monthly payments.
• Lump-sum payments: apply a windfall directly to principal whenever you can.

Do biweekly payments really pay off a loan faster? Yes. You make 26 half-payments per year, which equals 13 full payments instead of 12. The extra payment goes entirely toward principal. On a 30-year mortgage, biweekly payments typically shave about 4 to 5 years off the loan term.

What's prepaying your mortgage? Prepaying means making payments above the required amount. The extra goes toward your loan balance, reducing the total cost of the loan.

Loan Amortization vs. Adjustable-Rate Mortgage Repayment

This calculator is designed for a fixed-rate loan, where the interest rate stays the same for the entire loan term. The amortization schedule is predictable because every payment is identical.

An adjustable-rate mortgage (ARM) works differently. The rate is fixed for an initial period (often 5, 7, or 10 years), then adjusts periodically based on a market index. When the rate changes, the monthly payment changes, and the amortization schedule shifts.

Does my amortization schedule change if the interest rate changes? Yes. Any rate change recalculates the remaining balance over the remaining term at the new rate. That is why an amortized loan with a fixed rate is easier to plan around. You know every payment from day one.

You can still use this calculator to model an ARM's initial fixed period. Just enter the introductory rate and the number of fixed years as your loan term. Keep in mind the results only reflect that initial period.

Reading Your Calculator Results

After you hit calculate, you will see:

• Estimated monthly payment: your monthly principal and interest payment. This does not include property taxes, homeowners insurance, or private mortgage insurance (PMI). Your actual mortgage payment to a lender will likely be higher once those costs are added.
• Total interest paid: the sum of all interest over the life of the loan.
• Total cost of the loan: principal plus total interest.
• Payoff date: when you will make your last payment, including the effect of any extra payments.
• Amortization schedule: the full month-by-month table.

Is the interest rate used in the calculator the same as the APR? No. The calculator uses the note rate (the interest rate on the loan itself). APR includes origination fees, discount points, and other costs rolled into an annualized figure. Your APR will usually be slightly higher than your note rate.

What are mortgage points? Points are upfront fees paid to the lender to lower your interest rate. One point typically costs 1% of the loan amount and reduces the rate by about 0.25%. This calculator does not factor in points, but you can enter the reduced rate to see the effect on your amortization schedule.

Will an amortization calculator account for additional fees or costs? No. This calculator estimates principal and interest only. Property taxes and homeowners insurance are not included. Use the results as a planning starting point, not a final budget.

How This Payment Calculator Compares to Other Loan Calculators

Loan calculators serve different purposes. Here is how this tool fits in:

• Basic payment calculator: shows only the monthly payment amount. No schedule.
• Amortization calculator: shows the monthly payment plus a full amortization schedule with principal, interest, and balance for every payment. That is this tool.
• Payoff calculator: focuses on how quickly you can pay off your loan with extra payments or lump sums.
• Refinance calculator: compares your current mortgage with a new loan to estimate savings.

This amortization calculator lets you do more than a basic payment calculator because you get the complete schedule. And because it includes an extra payment field, it doubles as a payoff planning tool.

What types of loans can this calculator handle? Any amortized loan with a fixed rate and fixed term. That includes conventional mortgages, FHA loans, VA loans, auto loans, and personal loans. If the loan has equal periodic payments over a set term, this calculator works.

Is an amortization calculator useful for evaluating refinancing options? Yes. Run your current loan details, then run the proposed new loan. Compare total interest paid and payoff timelines to see whether refinancing makes financial sense for your situation.

Amortization Calculator Estimates and Limitations

This calculator provides estimates for planning purposes. It is not a loan offer, a commitment to lend, or financial advice.

Keep these limitations in mind:

• Results show principal and interest only. They do not include property taxes, homeowners insurance, PMI, or HOA fees.
• The calculator assumes a fixed interest rate for the entire loan term.
• It does not account for escrow adjustments, late fees, or prepayment penalties.
• Rounding may cause minor differences compared to your lender's official amortization table.
• Information and interactive calculators are made available as self-help tools. They do not replace guidance from a qualified mortgage professional.

For the most accurate picture, confirm your numbers with a lender before making financial decisions. Use this tool to explore scenarios, compare loan terms, and understand how your payments work. The schedule helps you plan, and planning is the first step toward making confident choices about your mortgage.