For auto, personal, or student loans — any fixed-rate installment loan. Adjust the amount, rate, and term to see your real monthly payment and full payoff schedule.
Get matched with a lender →Add a bit extra each month to see the payoff-time and interest impact.
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Enter the amount you're borrowing, the APR you were quoted (or expect), and the repayment term. The calculator applies the same fixed-rate amortization formula lenders use, splitting every payment between interest and principal so you can see exactly where your money goes each month.
The underlying math is the same fixed-rate amortization for all three, but the typical terms differ: auto loans usually run 3–7 years with rates tied to your credit and the vehicle's age, personal loans are often 2–7 years and unsecured (so rates run higher), and student loans can extend past 10 years with rates that vary by whether they're federal or private. Federal student loans also have income-driven repayment and forgiveness options this calculator doesn't model — check studentaid.gov for those specifics.
Almost always, yes — even though the monthly payment is lower, you're paying interest for more months. Use the schedule table to compare total interest across different terms.
Not quite. APR typically includes certain fees on top of the interest rate, spread across the loan term, which makes it the more accurate number for comparing two loan offers.
It varies by lender and loan type, but generally scores above 700 unlock meaningfully better rates on personal and auto loans, while scores below 600 often mean higher rates or the need for a co-signer.
This calculator provides estimates for planning purposes only and is not a loan offer or credit approval. Actual rates and terms depend on your lender, credit profile, and loan type — confirm final numbers with your lender before signing.
The underlying math — amortization based on principal, interest rate, and term — is the same whether you're evaluating a personal loan, an auto loan, a student loan refinance, or any other fixed-payment installment loan. What differs between loan types in the real world is typically the interest rate range and term length lenders offer, not the calculation itself. Enter your specific numbers above and the calculator will build an accurate payment schedule regardless of what the loan is for.
Simple interest is calculated only on the original principal for the life of the loan, so the interest cost is fixed and predictable from day one. Amortized interest — what most installment loans, including this calculator, use — is calculated on the *remaining* balance each period, meaning your interest cost shrinks as you pay down principal. This is why an amortized loan's early payments are interest-heavy and later payments are principal-heavy, even though the total payment stays flat. Understanding which type your loan uses matters because it changes how much benefit you get from paying extra early versus late in the term.
Significantly, and often in a less intuitive way than people expect. A longer term lowers your monthly payment by spreading the same principal across more payments — but it also means interest accrues for longer, so the total amount you pay back goes up, sometimes substantially. A shorter term raises the monthly payment but reduces total interest. On a $20,000 loan, stretching from 3 years to 6 years at the same rate can nearly double the total interest paid, even though the monthly payment drops significantly. Try both term lengths above to see the actual dollar tradeoff for your loan amount.
Yes, and often even more noticeably, since personal and auto loans typically have shorter terms than mortgages, so extra payments have an outsized effect on the payoff timeline. Every extra dollar applied to principal reduces the balance interest is calculated against for every remaining payment. If your loan doesn't have a prepayment penalty (most personal loans don't, but it's always worth confirming with your specific lender), adding even a small extra amount consistently can meaningfully shorten your payoff date and reduce what you pay in total interest. Add an extra payment amount above to see your adjusted schedule.
An amortization schedule is simply the full breakdown of every payment over the life of your loan, showing exactly how much of each payment goes to principal versus interest, and what your remaining balance is after each one. It matters because it turns an abstract monthly payment number into a concrete picture of your loan's trajectory — you can see precisely when you'll cross the halfway point, how much total interest you'll have paid by any given month, and how extra payments shift that timeline. The schedule generated above updates instantly as you adjust your loan details, so you can compare scenarios side by side before committing to anything.
Look past the monthly payment number and compare the total cost of the loan — principal plus total interest — across offers with the same loan amount. Two loans with similar monthly payments can have very different total costs if their terms or rates differ. It's also worth checking whether the rate is fixed or variable, whether there are origination fees (which effectively raise your true cost even if they're not baked into the advertised rate), and whether a prepayment penalty exists. Plugging a specific offer's rate and term into the calculator above gives you the real total cost to compare against other quotes.
Because the interest rate alone doesn't capture everything — fees, the compounding method, and the exact term length all affect the true cost. A loan with an origination fee deducted from your disbursed amount effectively costs more than the stated rate suggests, since you're paying interest on the full amount but only receiving the reduced amount. This is part of why APR (which factors in most fees) is usually a more reliable number for comparing loans than the bare interest rate alone.
Lenders typically weigh your credit score and credit history most heavily, followed by your income and existing debt relative to that income (your debt-to-income ratio), the loan amount and term you're requesting, and — for secured loans like auto loans — the value and age of whatever's backing the loan. Two people borrowing the identical amount for the identical term can receive meaningfully different rates based on these factors. Running the numbers at a few different plausible rates above can help you understand your realistic range before you apply, so you're not caught off guard either way.
This depends mainly on your loan's interest rate versus your realistic expected return elsewhere. If your loan carries a high interest rate, paying it down early essentially guarantees you that rate as a "return," since every dollar of principal you eliminate stops accruing interest at that rate immediately. If your loan's rate is low, the math sometimes favors investing instead, since long-term market returns can exceed low loan rates — though that comes with more risk and no guarantee. There's no single right answer for everyone; it depends on your rate, your risk tolerance, and your other financial goals. The calculator above can at least show you the guaranteed savings side of the equation, so you know exactly what paying early buys you.
The payment math itself is precise for whatever rate and term you enter — that part won't change. What can differ is the actual rate a lender offers you once they've reviewed your full application, since that depends on factors (credit pull results, verified income, debt-to-income ratio) that a calculator can't see in advance. Using this tool with a few realistic rate scenarios based on your credit range gives you a solid, well-informed estimate to walk into any conversation with, so you already understand what a fair payment looks like before you're presented with an offer.