Amortization Calculator

Calculate your monthly payment and see how principal, interest, and your remaining loan balance change over time.

Loan Results

Monthly Payment $0.00
Loan Amount $0.00
Total Interest $0.00
Total Payment $0.00

Amortization Schedule

Year-by-year breakdown of principal, interest, and remaining loan balance.

Year Principal Paid Interest Paid Remaining Balance
Calculate your loan to see the amortization schedule.

About the Amortization Calculator

The Numelios Amortization Calculator shows how a fixed-rate loan can be paid down over time. It breaks scheduled payments into principal and interest and helps estimate the remaining loan balance throughout the repayment period.

An amortization schedule can help borrowers understand why interest makes up a larger share of many early loan payments and how principal repayment gradually increases as the balance declines.

How Loan Amortization Works

With a standard fixed-rate amortizing loan, the scheduled principal and interest payment generally remains the same while the amount allocated to principal and interest changes over time.

Interest = Remaining Balance × Periodic Interest Rate
Principal = Scheduled Payment − Interest

The principal portion reduces the outstanding balance. Interest for the following period is then calculated using the new, lower balance.

Amortization Example

Consider a $300,000 mortgage with a 6.5% fixed interest rate and a 30-year term.

Loan Amount $300,000
Interest Rate 6.5%
Loan Term 30 years
Payments 360 monthly

Early payments generally contain more interest and less principal. As the balance falls, the interest portion decreases and more of each scheduled payment goes toward principal.

Principal vs. Interest

Principal

Principal is the amount borrowed. The principal portion of each payment reduces the remaining loan balance.

Interest

Interest is the borrowing cost charged on the outstanding principal balance according to the loan's interest rate.

Remaining Balance

The remaining balance is the unpaid principal after scheduled and eligible additional principal payments have been applied.

Total Interest

Total interest represents the accumulated interest paid over the repayment period under the assumptions used.

Why Do Early Mortgage Payments Include More Interest?

Interest is calculated using the outstanding balance. Near the beginning of a mortgage, the balance is close to the original loan amount, so the interest charge is relatively high.

As principal is repaid, the outstanding balance decreases. That generally reduces the interest charged each month and allows a larger share of the scheduled payment to reduce principal.

How Loan Term Affects Amortization

A longer repayment term generally produces a lower required monthly payment because repayment is spread across more payments. However, the borrower may pay substantially more interest over the full term.

A shorter term generally requires a higher monthly payment but pays principal down faster and may substantially reduce total interest.

Use the Mortgage Calculator to compare monthly payment estimates for different rates and terms.

How Extra Payments Affect an Amortization Schedule

Additional payments applied directly to principal can reduce the outstanding balance faster. Because future interest is calculated using a smaller balance, this may shorten the repayment period and reduce total interest.

Use the Mortgage Payoff Calculator to explore how additional principal payments may affect payoff time and estimated interest savings.

Frequently Asked Questions

What is an amortization schedule?

An amortization schedule shows scheduled loan payments over time and typically identifies the amount allocated to principal, interest, and the remaining balance after each payment.

Why does the principal portion increase over time?

As the outstanding balance declines, less interest is generally charged each period. With a fixed scheduled payment, more of the payment can therefore be applied to principal.

Does amortization include property taxes and insurance?

Loan amortization generally describes principal and interest. Property taxes, homeowners insurance, mortgage insurance, HOA fees, and other housing expenses are separate unless a specific calculator explicitly includes them.

Can I change an amortization schedule with extra payments?

Additional principal payments can reduce the balance faster and may change the effective payoff date and total interest paid. Loan terms and servicer procedures should be checked before making additional payments.

What happens with a shorter loan term?

A shorter term usually increases the required monthly payment but pays down principal more quickly and can reduce total interest compared with a longer term at the same rate.

This calculator is provided for informational and educational purposes only. Results are estimates based on the values entered and may differ from an actual lender or loan servicer amortization schedule.