Loan Payoff Calculator
Free Loan payoff Calculator for loans & mortgages. Enter your numbers to see returns, costs, and optimized scenarios instantly.
Formula
n = -log(1 - r x PV / PMT) / log(1 + r)
Where n = number of months to payoff, r = monthly interest rate (annual rate / 12), PV = present value (loan balance), PMT = monthly payment. Total interest = (n x PMT) - PV. The calculator runs both standard and accelerated (with extra payment) amortization schedules to show the comparison.
Worked Examples
Example 1: Auto Loan Early Payoff
Problem: You have a $20,000 auto loan at 5.9% APR with $400 monthly payments. How much do you save by adding $150 extra per month?
Solution: Standard: Monthly rate = 0.492%\nPayoff time = -log(1 - 0.00492 x 20000/400) / log(1.00492) = 56 months\nTotal interest = $2,340\n\nWith $150 extra ($550/month):\nPayoff time = 40 months\nTotal interest = $1,608\nSavings = $2,340 - $1,608 = $732\nTime saved = 16 months
Result: Save $732 in interest and pay off 16 months early
Example 2: Student Loan Payoff Comparison
Problem: You owe $35,000 in student loans at 6.8% with $450 minimum payment. Compare paying $100, $200, and $300 extra per month.
Solution: Standard ($450): 103 months, $11,454 interest\n+$100 ($550): 78 months, $8,447 interest, save $3,007\n+$200 ($650): 63 months, $6,667 interest, save $4,787\n+$300 ($750): 53 months, $5,504 interest, save $5,950\nDiminishing returns: each extra $100 saves less than the previous
Result: +$100 saves $3,007 | +$200 saves $4,787 | +$300 saves $5,950
Frequently Asked Questions
What is the difference between principal and interest in a loan payment?
Each loan payment is split between principal (reducing your actual debt) and interest (the cost of borrowing). In the early months of a loan, most of your payment goes toward interest because interest is calculated on a larger remaining balance. As you pay down the principal, the interest portion shrinks and more of each payment goes toward principal. This process is called amortization. For example, on a $25,000 loan at 6.5%, your first monthly payment of $500 includes approximately $135 in interest and $365 toward principal. By the final payment, nearly the entire amount goes to principal. Understanding this split explains why extra payments early in the loan have a disproportionately large impact on total interest paid.
How do I calculate when my loan will be paid off?
The loan payoff formula determines the number of months needed: n = -log(1 - (r x PV / PMT)) / log(1 + r), where r is the monthly interest rate, PV is the loan balance, and PMT is the monthly payment. This formula accounts for the decreasing interest charge as principal is paid down. For a $25,000 loan at 6.5% with $500 monthly payments: r = 0.065/12 = 0.005417, so n = -log(1 - (0.005417 x 25000 / 500)) / log(1.005417) = approximately 57 months (4 years, 9 months). Loan Payoff Calculator performs this computation automatically and also shows the accelerated payoff date when extra payments are applied, giving you a clear picture of how extra payments shorten your repayment timeline.
What types of loans benefit most from early payoff?
Loans with higher interest rates benefit the most from early payoff because each dollar of extra payment saves more in future interest. Credit card debt (15-25% APR) provides the highest return on extra payments. Personal loans (8-15% APR) also benefit significantly. Auto loans (4-8% APR) offer moderate benefits. Student loans (4-7% APR) are a middle ground, though some have tax-deductible interest. Mortgages (6-8% APR currently) benefit from extra payments, but the large balance means substantial savings in absolute dollars even at lower rates. Loans with prepayment penalties should be evaluated carefully because the penalty might offset savings from early payoff. Always verify your loan has no prepayment penalty before making extra payments.
How does the interest-to-principal ratio help me understand loan costs?
The interest-to-principal ratio shows what percentage of your original loan amount you pay in total interest charges. A ratio of 30% means you pay $30 in interest for every $100 borrowed. This metric makes the true cost of borrowing immediately tangible. Short-term loans typically have ratios of 5-15%, while long-term mortgages can have ratios exceeding 100% (you pay more in interest than you borrowed). By comparing the standard and accelerated payoff scenarios in Loan Payoff Calculator, you can see exactly how extra payments reduce this ratio. Going from a 25% ratio to 18% through extra payments means meaningful savings. This metric is particularly useful when comparing different loan offers or deciding whether refinancing makes financial sense.
How does biweekly payment scheduling accelerate loan payoff?
Biweekly payments work by paying half your monthly payment every two weeks instead of the full amount once per month. Since there are 52 weeks in a year, you make 26 half-payments, which equals 13 full monthly payments per year instead of 12. That extra payment goes entirely toward principal reduction. On a $25,000 loan at 6.5%, biweekly payments of $250 (half of $500) would effectively add one extra $500 payment per year, paying off the loan approximately 5-6 months early and saving several hundred dollars in interest. This strategy works because you barely notice the difference in cash flow (you still pay the same per paycheck) but the extra annual payment makes a meaningful impact over time.
Can I use Loan Payoff Calculator on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.