Calculate monthly payments, total interest, and view a full amortization schedule for any fixed-rate loan โ plus model extra payments to see how much you can save.
This free repayment calculator works for any fixed-rate installment loan โ personal loans, auto loans, mortgages, student loans, business loans, or home equity loans. Enter the principal amount, annual interest rate, and loan term in months or years. The calculator returns your monthly payment amount, total amount paid over the life of the loan, total interest cost, and a month-by-month amortization table. An optional extra-payment field shows how making additional principal payments each month affects your payoff date and total interest. The calculator assumes a fixed interest rate; for variable-rate loans, use the initial rate to model the starting repayment schedule, then recalculate when the rate adjusts.
1. Enter the loan principal (the amount borrowed, not including interest).
2. Enter the annual interest rate as a percentage (e.g., 7.5 for 7.5%).
3. Select the loan term โ enter in years or months.
4. Optionally enter an extra monthly payment amount to model accelerated payoff.
5. Click "Calculate" to see your monthly payment, total interest, and total repayment cost.
6. Scroll down to view the full amortization schedule and see how each payment splits between interest and principal over time.
The standard loan repayment formula is:
Monthly Payment (M) = P ร [r(1+r)^n] รท [(1+r)^n โ 1]
Where P = principal, r = monthly interest rate (annual rate รท 12), and n = total number of monthly payments. Example: a $20,000 loan at 8.5% for 5 years โ r = 0.085 รท 12 = 0.00708; n = 60; M = $20,000 ร [0.00708 ร (1.00708)^60] รท [(1.00708)^60 โ 1] = approximately $410/month. Total repaid = $410 ร 60 = $24,600. Total interest = $4,600. Each monthly payment reduces the principal by (M โ interest accrued), with interest front-loaded in early payments.
Your monthly payment stays constant throughout a fixed-rate loan, but what's inside it shifts dramatically over time. Early payments are mostly interest; later payments are mostly principal. This is amortization in action. If your result shows more total interest than you expected, the most powerful lever is loan term โ shortening from 5 years to 3 years on a $20,000 loan at 8.5% cuts total interest from ~$4,600 to ~$2,700 while raising the monthly payment by about $200.
Amortization is the process by which your fixed monthly payment is divided between interest and principal, following a mathematical schedule that always applies interest first. On a $30,000 personal loan at 9% for 6 years (72 months), your monthly payment is approximately $540. In month 1, $225 goes to interest ($30,000 ร 9% รท 12) and $315 reduces principal. By month 36 (halfway through), the split has shifted to roughly $136 interest and $404 principal โ but you still owe about $16,200 despite 36 payments. That's the nature of amortization: the first half of your payments retire less than half the debt.
This front-loading has a crucial implication: if you pay off a loan early โ by refinancing, selling the asset, or making a lump-sum payment โ you've already paid the most interest-heavy portion and get the least benefit from prepaying late in the schedule. Conversely, making extra payments early in the loan life (months 1โ24 on a long-term loan) eliminates future interest most aggressively. The amortization schedule your calculator generates makes this visible, row by row.
Extra payments are one of the highest-return financial moves available to any borrower, and the numbers are often surprising. Consider a $25,000 auto loan at 7.2% for 60 months. Monthly payment: approximately $496. Total interest at the standard schedule: $4,760.
Add $100/month in extra principal payments:
Add $250/month extra:
The savings compound faster than linear intuition suggests because each extra dollar of principal eliminates all the future interest that would have accrued on it for the remaining term. On a 30-year mortgage, a $200/month extra payment on a $350,000 balance at 6.5% can cut the payoff by 6+ years and save over $100,000 in total interest โ a result that almost no borrower realizes until they run the numbers.
This calculator assumes a fixed rate, which means the monthly payment is identical from month 1 to the final payment. Fixed-rate repayment is predictable and easy to budget. Variable-rate loans (some personal loans, HELOCs, adjustable-rate mortgages) work differently: the rate โ and therefore the payment โ can change periodically.
For variable-rate loans, use this repayment calculator to model the current payment, but plan conservatively. With the prime rate at 6.75% in 2026 and variable loan rates commonly indexed to prime or SOFR, a rate increase of 1โ2 percentage points is a realistic stress test. On a $15,000 variable-rate personal loan:
Model the current rate, then rerun at +2% and +4% to understand your worst-case exposure. If the higher-rate scenario is unaffordable, a fixed-rate loan is the safer choice even if the current variable rate is lower.
The amortization schedule your repayment calculator generates is a negotiating tool, not just information. Here's how:
Compare true cost, not monthly payment. Lenders frequently advertise low monthly payments by extending the loan term. A 7-year auto loan at 6% has a lower monthly payment than a 5-year loan at 6%, but costs substantially more in total interest. Running both through this calculator instantly reveals the full-cost comparison.
Understand prepayment penalties before committing. Some personal loans and auto loans carry prepayment penalties โ fees charged if you pay off the loan early. If you plan to make extra payments, confirm whether your loan agreement includes a prepayment penalty. A 2% prepayment penalty on a $20,000 loan = $400, which can offset months of interest savings from extra payments.
Use the amortization table to time refinancing. Refinancing makes the most sense when you still have a large principal balance and future interest remaining. The amortization schedule shows exactly how much principal you owe at any future month โ the optimal refinancing window is typically before you've crossed the midpoint of your original loan term.
Interest rate: The dominant variable in your total cost. A 1-percentage-point rate difference on a $20,000 loan over 5 years changes total interest by roughly $550โ$600. Always compare APR (which includes fees) rather than nominal rate when shopping lenders. Average personal loan rates for borrowers with 700+ credit scores run approximately 12.28% in 2026, with well-qualified borrowers accessing rates as low as 6.2%.
Loan term: Longer terms reduce monthly payments but increase total interest substantially. Every additional year multiplies the interest cost by extending the period principal remains outstanding.
Principal amount: Obvious, but often underweighted โ borrowers focus on monthly payment affordability without scrutinizing whether the total loan amount makes sense for the purpose.
Origination fees: Many personal loans charge 1โ8% origination fees deducted from the disbursed amount or added to principal. These effectively raise your APR above the stated rate.
Marcus in Nashville is borrowing $18,000 for a kitchen renovation. He qualifies for a personal loan at 9.4% and is considering either a 3-year or 5-year term. Using the repayment calculator: 3-year term โ monthly payment $574, total interest $2,664, total cost $20,664. 5-year term โ monthly payment $376, total interest $4,560, total cost $22,560. The 5-year payment is $198/month lower, but costs $1,896 more in interest. Marcus decides the $198/month difference is manageable in his budget and chooses the 3-year term to minimize total cost โ a decision made confidently only because he ran both scenarios side by side.
Priya refinanced her graduate student loans into a single private loan of $42,000 at 7.5% for 10 years. Standard monthly payment: $501. Total interest over 10 years: $18,120. Her repayment calculator shows that adding $150/month in extra principal payments cuts her payoff to approximately 7.5 years and reduces total interest to roughly $12,800 โ saving $5,320 and cutting 2.5 years off her debt. With federal graduate loan rates at 7.94% for 2025โ26, her refinanced private loan at 7.5% is marginally better, but she's also lost federal IDR protections โ a trade-off she evaluated carefully before refinancing.
1. Run total cost comparisons, not just monthly payments. The calculator's "total interest paid" figure is the number that matters for lifetime cost. Monthly payment comparisons alone can mislead you into longer, more expensive loans.
2. Set up autopay. Most lenders discount the rate by 0.25โ0.50% for automatic payments. On a $25,000 loan at 7%, a 0.25% rate reduction saves roughly $185 over a 5-year term โ free money for a 2-minute account setup.
3. Make one extra payment per year. A 13th annual payment on a 30-year mortgage cuts the payoff by approximately 4 years. The same principle applies to personal and auto loans.
4. Apply windfalls to principal directly. Tax refunds, bonuses, or unexpected income applied as lump-sum principal payments early in the loan life generate the highest interest savings per dollar.
5. Review your amortization table annually. Knowing your current principal balance and remaining interest gives you the information needed to evaluate refinancing, extra-payment strategies, or loan consolidation decisions.
A: A repayment calculator computes the monthly payment required to fully repay a loan of a given principal, interest rate, and term. It also shows total interest paid over the life of the loan and generates a month-by-month amortization table breaking down each payment into interest and principal components.
A: Your monthly payment uses the amortization formula: M = P ร [r(1+r)^n] รท [(1+r)^n โ 1], where P is the principal, r is the monthly interest rate (annual rate divided by 12), and n is the total number of payments. This produces a fixed payment that satisfies the debt in exactly n months.
A: An amortization schedule is a complete table of all loan payments, showing how each payment divides between interest and principal, the running balance after each payment, and cumulative interest paid. Early payments are heavily weighted toward interest; the principal share grows over time.
A: The savings depend on your loan balance, rate, and how early in the term you start making extra payments. As a practical rule, an extra $100/month on a $20,000 personal loan at 8.5% for 5 years saves roughly $500โ$700 in interest and cuts approximately 8โ10 months off the payoff. Larger loans at longer terms magnify savings dramatically.
A: Yes โ the underlying math is identical for any fixed-rate installment loan. Enter the mortgage principal, interest rate, and term (e.g., 360 months for a 30-year loan) to see monthly payment, total interest, and amortization schedule. For a complete mortgage analysis including taxes, insurance, and PMI, use the dedicated Mortgage calculator.
A: A repayment calculator models a single loan's payment schedule โ it tells you the cost of a fixed loan over its term. A debt payoff calculator handles multiple debts simultaneously and helps you prioritize which to pay first (avalanche vs. snowball method) to minimize total interest across your entire debt load.
A: APR (Annual Percentage Rate) includes origination fees, closing costs, and other charges rolled into the annual rate, making it higher than the nominal interest rate. This calculator uses the interest rate you enter, which is typically the stated (nominal) rate. To model the true cost including fees, convert your APR to an equivalent interest rate or add fees to the principal amount you enter.
A: This calculator models fixed-rate repayment. For variable-rate loans, enter the current interest rate to see today's payment schedule. Rerun the calculation with higher rates (+2%, +4%) to stress-test your budget. For a HELOC or adjustable-rate mortgage, check the rate-adjustment caps in your loan agreement and model the maximum possible rate as a worst-case scenario.
Brief disclaimer: This calculator provides estimates for educational and planning purposes only. Actual loan terms, interest rates, and repayment schedules depend on lender approval, creditworthiness, and applicable loan agreements. Results assume a fixed interest rate for the full loan term. Prepayment penalties, origination fees, and other lender-specific charges are not accounted for unless manually entered. Consult your lender or a qualified financial professional before making borrowing decisions.