Estimate your monthly, bi-weekly, or weekly loan payment, total amount repaid, and total interest on a fixed-rate loan. You can also test extra principal payments and one-time lump sums to see how they may change your payoff timeline.
Example: add $100 to each payment to potentially reduce interest and shorten payoff time.
Example: apply a bonus or tax refund as a one-time principal reduction.
Payment #1 is the first scheduled payment after loan origination.
This setting affects displayed values only. Lenders may round differently.
This calculator uses standard fixed-rate amortization math and assumes the interest rate stays the same for the full term. Results are estimates and may differ from lender statements due to fees, escrow, taxes, insurance, compounding conventions, or payment processing rules.
This tool is designed to help you understand the math behind a fixed-rate installment loan. It is useful for quick payment estimates, payoff comparisons, and planning how extra payments may affect total interest.
This calculator is best for borrowers comparing fixed-rate personal loans, auto loans, and other installment loans. It is especially useful if you want to estimate your payment, understand how amortization works, or test whether adding extra principal could reduce interest.
This page estimates principal-and-interest math only. It does not automatically include origination fees, taxes, insurance, escrow, late charges, refinance costs, or lender-specific servicing rules. Those details can change the real payment.
The calculator uses standard fixed-rate amortization math. Payment estimates are based on loan amount, nominal annual interest rate, payment frequency, and total number of periods. Extra principal is modeled as an immediate reduction in balance after the scheduled payment for that period.
This loan payment calculator estimates how much you may pay on a fixed-rate, amortizing installment loan. You enter a loan amount, annual interest rate, loan term, and payment frequency. The calculator then estimates your periodic payment, total amount repaid, and total interest cost. It also shows a preview of the first 12 payments so you can see how principal and interest change over time.
That principal-and-interest split matters because it explains a common borrower surprise: early payments often seem to reduce the balance more slowly than expected. This is how amortization works. Interest is calculated on the remaining balance, so when the balance is high, the interest portion is also higher. As the balance falls, the interest portion generally shrinks and more of each payment goes toward principal.
A loan payment is the amount you pay to a lender on a schedule, most commonly monthly, but sometimes bi-weekly or weekly. Each payment is usually split into two parts: principal, which reduces the balance, and interest, which is the cost of borrowing.
With a standard amortizing loan, the payment amount usually stays the same if the rate is fixed, but the principal/interest split changes over time. This is why two loans with similar monthly payments can still have very different total borrowing costs depending on the rate and term.
This calculator is built for fixed-rate loans, meaning the interest rate stays the same for the full term. That makes the payment pattern more predictable than with adjustable-rate or variable-rate products. Many personal loans and auto loans use this structure, and some mortgages do too.
If your loan has a variable or adjustable rate, your future payment may change when the rate changes. In that case, a fixed-rate calculator is still helpful for baseline understanding, but it may not match future lender statements exactly.
The calculator converts your annual rate into a periodic rate by dividing it by the number of payments per year (12 for monthly, 26 for bi-weekly, 52 for weekly). It then uses a standard amortization formula to calculate the fixed payment needed to fully repay the balance by the end of the term.
If the interest rate is 0%, the loan balance is simply spread evenly across the number of payments. In real lending, a 0% offer may still have fees or conditions, so that scenario should be treated as a simple math model rather than a full loan quote.
An amortization schedule breaks down each payment into principal and interest and tracks the remaining balance after every payment. On this page, you see the first 12 payments for the scheduled plan. This makes it easier to visualize how fixed payments behave over time.
If you want to compare borrowing scenarios, try changing the loan term. Shorter terms usually increase the payment but reduce total interest. Longer terms may lower the payment, but often increase total lifetime borrowing cost. For home-loan-style comparisons, see the Mortgage Calculator.
Many borrowers use “APR” and “interest rate” as if they mean the same thing. They are related, but not identical. Understanding the difference helps you compare loans more fairly, especially when lenders include fees.
The interest rate is the percentage used to calculate borrowing cost on the remaining balance. It is the main number used in amortization math and directly affects how much interest you pay over time.
APR, or Annual Percentage Rate, is intended to reflect a broader annualized borrowing cost. Depending on the product and jurisdiction, APR may include certain fees in addition to the stated interest rate. That makes it useful when comparing similar loan offers from different lenders.
On this page, the payment estimate is based on the interest rate you enter. If you want a dedicated explainer, see APR vs APY – What’s the Difference?.
Refinancing means replacing an existing loan with a new one. In practice, most refinance decisions come down to two questions: does the new loan reduce total interest enough to justify any fees, and does the new term fit your broader budget plan?
A lower rate often helps, but extending the term can reduce the monthly payment while increasing total interest over a longer time horizon. That is why refinance math should be evaluated using both payment size and total lifetime cost.
A practical way to compare scenarios is to run your current remaining balance and time left at the current rate, then run the new rate and new term as a second scenario. That provides a quick estimate of whether the payment improvement is worth the longer timeline.
Paying extra toward principal is one of the simplest ways to change loan math without changing lenders or refinancing. It reduces the balance faster, which can shorten the payoff timeline and lower total interest.
The reason is mechanical: interest is calculated from the remaining balance. If the balance is reduced sooner, future interest charges are usually lower. In many loans, the required scheduled payment does not change, but the number of payments needed to reach zero may shrink.
A standard amortizing loan is designed to hit a zero balance exactly at the end of the original term. If you add extra principal regularly, you are paying down the balance faster than the original schedule assumed. That typically means you can finish in fewer payments.
Total interest is closely tied to how much balance remains outstanding and for how long. When you reduce the “balance × time” exposure, total interest can fall. This is why small extra payments repeated consistently can have a noticeable effect over time.
Borrowers usually use one of two approaches:
Monthly extra can be powerful because it repeatedly reduces the balance. A lump sum can still help, especially when applied earlier, because earlier reductions affect more future interest periods.
Personal loan example: $10,000 at 8% over 4 years.
Auto loan example: $25,000 at 6% over 5 years.
Extra payment example: Add $50 or $100 per payment and compare the payoff timeline side by side.
If you want to compare debt payoff with steady saving, the Savings Goal Calculator can help you model the tradeoff.
Monthly, bi-weekly, and weekly payment comparisons can be useful when your lender applies each payment as it is made. In that case, more frequent payments may reduce balance slightly sooner and can lower interest in some situations.
However, not all lenders process payments the same way. Some hold partial payments and post them later. That means the real savings from payment frequency changes can differ from the simple estimate shown here.
What happens if I pay extra toward principal?
Extra principal reduces your balance faster, which can shorten the payoff timeline and reduce total interest.
The impact depends on the size and timing of extra payments and how your lender applies them.
Is APR the same as the interest rate?
Not always. The interest rate drives the amortization math. APR is intended to reflect a broader annualized cost
and may include certain fees. For loan comparisons, APR can be more apples-to-apples when fees differ.
Do weekly or bi-weekly payments always save interest?
Not always. If payments are applied each period and reduce the balance sooner, interest can drop.
But if the lender holds payments and applies them monthly, savings may be smaller.
How does refinancing change the math?
Refinancing replaces the loan. A lower rate can reduce interest, but restarting a longer term can increase total interest
even if the payment drops. Fees also affect the break-even point.
Does this calculator include fees, taxes, or insurance?
No. This calculator estimates principal and interest only. Fees, taxes, insurance, escrow, and penalties can change the real payment.
This loan payment calculator is intended for informational and educational purposes only. It does not provide financial, legal, or tax advice and does not represent a loan offer. Always review your lender documents carefully before making borrowing or repayment decisions.