Loan Amortization Calculator

Work out the monthly payment on a fixed-rate loan and see how every payment splits between principal and interest — with the total interest and a full repayment schedule.

Your loan
Loan term
Results
Monthly payment
Total interest
Total paid
Amortization schedule
MonthPrincipalInterestBalance
Enter the loan amount, interest rate and term to see the monthly payment.

Every calculation runs in your browser — the figures you enter never leave your device.

FAQ

How is the monthly payment worked out?

It uses the standard amortization formula, so the same fixed amount every month clears the whole loan by the end of the term. A higher rate or a longer term adds to the total interest, while a shorter term raises the monthly payment but cuts the interest you pay overall.

What does the amortization schedule show?

Each payment is split into interest, charged on the balance you still owe, and principal, the rest that actually reduces the balance. Early on most of the payment is interest; as the balance falls, more goes to principal every month until it reaches zero.

Does it include taxes, insurance or extra payments?

No — it covers principal and interest at one fixed rate. A real mortgage payment can also carry property tax, insurance and lender fees, and paying more than the scheduled amount would clear the loan earlier than shown here.

Can I rely on this for a real loan?

Use it to compare options and understand the numbers, not as advice. The final payment is nudged by a few cents so the balance ends exactly at zero, and your lender’s rate, rounding and fees may differ — confirm with them before you commit.

Written and reviewed by the BroBroGo editorial team.Last updated:

Understanding Fixed-Rate Loan Amortization

A fixed-rate loan maintains the same interest rate throughout its entire duration. This stability means the monthly payment remains constant, but the internal distribution of each payment changes over time. This process of systematically paying off both the principal and the interest over a set period is known as amortization.

The standard amortization formula determines a fixed monthly payment that ensures the loan balance reaches exactly zero at the end of the term. Because interest is calculated based on the remaining balance, the portion of the payment allocated to interest is highest at the beginning of the loan. As the outstanding balance decreases, the interest portion shrinks, and a larger share of the monthly payment goes toward reducing the principal.

The Components of a Loan Payment: Principal and Interest

Every scheduled payment on an amortized loan consists of two primary components:

  • Principal: The actual money borrowed that goes directly toward reducing the outstanding loan balance.
  • Interest: The cost charged by the lender for borrowing the money, calculated as a percentage of the remaining unpaid balance.

Early in the loan term, most of the payment is interest; as the balance falls, more goes to principal. For example, even though the total monthly payment remains identical from month to month, the first payment of a loan will have the highest interest component, while the final payment will consist almost entirely of principal.

How Loan Term and Interest Rate Affect Total Cost

The total cost of borrowing is heavily influenced by the annual interest rate and the length of the loan term.

  • Interest Rate: A higher annual interest rate increases the interest charged each month, which raises both the monthly payment and the total interest paid over the life of the loan.
  • Loan Term: A longer term spreads the principal repayment over more months, which lowers the individual monthly payment. However, because the principal is paid down more slowly, interest accrues over a longer period, significantly increasing the total interest paid. Conversely, a shorter term raises the monthly payment but cuts the interest paid overall.

Interpreting an Amortization Schedule

An amortization schedule is a complete table detailing every periodic payment over the life of the loan. The schedule generated by this tool includes five distinct columns to track the progression of your repayment:

  • Month: The sequential number of the payment.
  • Year: The calendar year of the repayment schedule.
  • Principal: The specific portion of that month's payment applied to reduce the loan balance.
  • Interest: The portion of the payment that covers the interest accrued during that period.
  • Balance: The remaining unpaid loan principal after the current payment is applied.

In a standard schedule, the final payment is adjusted by a few cents to ensure the balance ends exactly at zero.

Using the Loan Amortization Calculator

To calculate your loan details, enter the required values into the input fields:

  • Loan amount: The total sum of money you intend to borrow.
  • Annual interest rate: The yearly interest rate charged by the lender.
  • Loan term: The duration of the loan, which can be entered in either Years (a whole number between 1 and 50) or Months (a whole number between 1 and 600).

Once valid inputs are entered, the tool displays the following results:

  • Monthly payment: The calculated fixed amount due each month.
  • Total interest: The total amount of interest paid over the life of the loan.
  • Total paid: The sum of the loan principal and the total interest.

A status message reading "Repaid over {n} monthly payments — estimate only." will appear upon successful calculation. If any input is invalid, the output fields for Monthly payment, Total interest, and Total paid will clear to "—".

Input Validation and Error Messages

The calculator enforces specific rules to ensure mathematical accuracy:

  • If the Loan amount or Annual interest rate is negative, the tool displays: "Loan amount and rate can’t be negative."
  • If the loan term falls outside the acceptable ranges, the tool displays: "Enter a whole number of years (1–50) or months (1–600)."
  • If the input numbers are too large for the system to process, the tool displays: "Those numbers are too large to calculate."
  • For any other invalid entries, the tool displays: "Enter valid numbers to calculate."

Privacy and Data Processing

Your financial privacy is maintained while using this tool. Every calculation runs in your browser, and the figures you enter never leave your device. No data is uploaded to external servers.

Estimated Calculations vs. Real Loan Offers

The results provided by this calculator are an estimate for planning only and are not financial, tax, or legal advice.

Actual loan offers from financial institutions may differ due to several factors:

  • Fees and Additional Costs: This tool does not include property tax, insurance, or lender fees in its calculations. A real mortgage payment, for instance, often bundles these items into an escrow account, raising the actual monthly out-of-pocket cost.
  • Prepayment Options: Paying more than the scheduled amount would clear the loan earlier than shown, reducing the total interest paid.
  • Lender Rules: Real loan offers depend on your lender's specific interest rate, rounding conventions, and terms. Always confirm the exact numbers with your lender before committing to a loan.

Frequently Asked Questions

How is the monthly payment worked out? It uses the standard amortization formula, so the same fixed amount every month clears the whole loan by the end of the term. A higher rate or a longer term adds to the total interest, while a shorter term raises the monthly payment but cuts the interest you pay overall.

What does the amortization schedule show? Each payment is split into interest, charged on the balance you still owe, and principal, the rest that actually reduces the balance. Early on most of the payment is interest; as the balance falls, more goes to principal every month until it reaches zero.

Does it include taxes, insurance or extra payments? No — it covers principal and interest at one fixed rate. A real mortgage payment can also carry property tax, insurance and lender fees, and paying more than the scheduled amount would clear the loan earlier than shown here.

Can I rely on this for a real loan? Use it to compare options and understand the numbers, not as advice. The final payment is nudged by a few cents so the balance ends exactly at zero, and your lender’s rate, rounding and fees may differ — confirm with them before you commit.

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