CALCULATOR · MONEY · LOANS
Financing $20,000 ($28,000 price − $3,000 down − $5,000 trade-in) at 6.5% APR for 60 months costs $391.32/month, with $3,479.20 in total interest and payoff in October 2031. Stretch that same loan to 84 months and the payment drops to $296.99 — but interest jumps to $4,947.16. Enter your own price, down payment, trade-in, rate, and term below.
Price minus down payment minus trade-in gives the amount financed; the standard amortization formula turns that into the monthly payment, the total interest, and the exact payoff month. The verdict tells you the all-in cost — payments plus everything you handed over at signing — and whether the term you picked is helping or hurting you.
Amount financed = price − down payment − trade-in. Monthly payment = P × r ÷ (1 − (1 + r)−n), with r = APR ÷ 12 and n = term in months. At the defaults: $28,000 − $3,000 − $5,000 = $20,000 financed; $20,000 × 0.0054167 ÷ (1 − 1.0054167−60) = $391.32/month; total of payments $23,479.20; total interest $3,479.20; all-in cost $31,479.20 (down + trade + all payments); payoff October 2031.
Setup: $28,000 car, $3,000 down, $5,000 trade-in, 6.5% APR, 60 months, purchased October 23, 2026.
The amount financed. $28,000 − $3,000 − $5,000 = $20,000.00 — the only number that actually earns interest. Every dollar of down payment or trade-in is a dollar that never touches the rate.
The monthly payment. Monthly rate r = 0.065 ÷ 12 = 0.0054167; payment = $20,000 × 0.0054167 ÷ (1 − 1.0054167−60) = $391.32/month. Sixty of those, like clockwork.
The total interest. $391.32 × 60 = $23,479.20 in payments; $23,479.20 − $20,000 = $3,479.20 in interest — about 17.4% of the financed amount. That’s the price of borrowing.
The all-in cost. $3,000 down + $5,000 trade + $23,479.20 in payments = $31,479.20 — what the car actually cost you, everything counted. (Depreciation isn’t in this number; it makes the picture worse.)
The payoff. October 23, 2026 + 60 months = October 2031.
Branch — the 84-month trap: same $20,000 at 6.5% for 84 months = $296.99/month — a $94.33/month discount. But interest totals $4,947.16, $1,467.96 more, and you pay until October 2033 — seven years on a car you’ll likely owe more than it’s worth for most of the loan. Lower payment, much higher cost.
Branch — 0% APR: $20,000 ÷ 60 = $333.33/month, $0.00 interest — a $3,479.38 gift from the automaker, when you can get it. (Factory 0% deals usually replace rebates — check whether the rebate-plus-higher-rate loan prices lower overall.)
Branch — $0 down: financed = $28,000 − $0 − $5,000 = $23,000 → $450.02/month, interest $4,001.20. Every dollar of down payment skipped costs you about 19¢ of monthly payment and puts you underwater the day you drive off.
Branch — used car ($18,000 at 8.9% for 48 months, no down/trade): financed = $18,000; payment = $447.08/month; interest = $3,459.84. The higher rate stings, but the shorter term and smaller price keep the interest comparable to the 60-month new-car loan.
| Output | Formula | What it means |
|---|---|---|
| Amount financed | price − down payment − trade-in | $20,000.00 at the defaults — the part of the car that earns interest. |
| Monthly payment | P × r ÷ (1 − (1 + r)−n) | $391.32 at the defaults — the fixed payment, principal + interest, for every month of the term. |
| Total interest | (payment × n) − financed | $3,479.20 at the defaults — the cost of borrowing, 17.4% of the financed amount. |
| All-in cost | down + trade-in + (payment × n) | $31,479.20 at the defaults — everything you paid for the car, out of pocket. |
| Payoff month | purchase date + term | October 2031 at the defaults — the month the last payment lands. |
This calculator models a simple fixed-rate amortizing loan with no fees — it does not include sales tax, title/registration, dealer doc fees, or insurance, all of which raise the true cost of buying the car. APR quotes are tiered by credit score: Experian’s Q2 2026 average new-car APR of 6.35% blends prime and subprime; your actual rate could be 4% or 12% depending on your score. Trade-in values in the calculator are optimistic inputs — enter a real offer, not a hope. Prepayment penalties exist on some auto loans; check your note before paying extra. Depreciation isn’t modeled — new cars lose ~20% in the first year, which is why the 84-month branch warns about being underwater.
Bright Side Kit. "Simple Auto Loan Calculator." https://brightoolbox.com/simple-auto-loan-calculator/ Accessed October 23, 2026.Data sourcesWith the standard amortization formula: payment = P × r ÷ (1 − (1 + r)−n), where P is the amount financed, r is the monthly rate (APR ÷ 12), and n is the term in months. At the defaults ($20,000, 6.5%, 60 months): $20,000 × 0.0054167 ÷ (1 − 1.0054167−60) = $391.32/month. The calculator shows every step so you can verify it.
Experian measured the average new-car loan APR at 6.35% in Q2 2026. Prime borrowers with top credit scores land near 5%; near-prime around 8–9%; subprime can exceed 13%. Your credit score is the single biggest lever on this number — improving it before you shop beats haggling over the sticker price.
Usually yes. On the $20,000 default loan, 84 months drops the payment to $296.99 but raises total interest from $3,479.20 to $4,947.16 — an extra $1,467.96. Worse, you’re upside-down (owing more than the car’s worth) for most of a seven-year loan, which traps you at trade-in time. The dealer sells the payment; buy the term.
Edmunds put the average new-vehicle transaction price at $44,664 in Q3 2026. The $28,000 default here is well below average — a modest new car or a nicer used one — which is exactly why financing $20,000 “only” costs $391.32/month. Run your actual price above.
Aim for at least 20% of the price if you can — it cuts the financed amount (and every interest dollar), and it’s your buffer against going underwater. At 6.5%/60mo, every $1,000 of down payment saves about $19.56/month and $173.60 in interest. The $0-down branch shows what skipping it costs: $450.02/month instead of $391.32.
Yes, but they replace rebates. A factory 0% deal on the $20,000 default = $333.33/month, $0.00 interest — genuinely free borrowing. But automakers usually offer 0% or a cash rebate: run both (the calculator’s 0% branch vs a lower price at 6.5%) and take the lower all-in cost, not the lower rate.
A trade-in reduces the financed amount dollar for dollar — the calculator’s $5,000 trade-in cuts the payment by about $97.83/month and saves $869.80 in interest. Private sales usually fetch 5–15% more, but take weeks and carry risk. Get a real cash offer (CarMax/Carvana/dealer), enter it above, and compare against the hassle.
Add the term to the purchase date — the calculator does it from the purchase-date field. At the defaults (Oct 23, 2026 + 60 months), the last payment lands in October 2031. Change either input to see your own payoff month.