Estimate your monthly car payment from price, down payment, trade-in, tax, rate, and term
In plain terms: it estimates the true monthly car payment you would actually make — built from the vehicle price, your down payment, any trade-in, sales tax, your APR, and the loan term in months. Enter your numbers and read the single monthly figure, plus how much you finance and how much interest the loan really costs. Everything runs in your browser — nothing you type is uploaded or stored.
Auto loan calculator estimates your true monthly car payment from the vehicle price, down payment, trade-in value, sales tax, interest rate, and loan term. Instead of guessing at the dealership, you can model any scenario in seconds and see exactly how each number moves your payment up or down. Everything runs in your browser, so none of the figures you type ever leave your device.
The math behind your payment happens in two stages. First, the calculator works out the amount you actually finance. It starts with the vehicle price, adds sales tax, then subtracts your down payment and the value of any trade-in. In most U.S. states, sales tax is charged on the price after the trade-in is deducted, which is why the trade-in helps you twice: once by shrinking the loan and again by shrinking the tax. The result is the loan principal — the amount the lender is really lending you.
Second, the calculator spreads that principal across your loan term using a standard amortization formula. Every fixed-rate car loan uses the same equation:
M = P × r × (1 + r)n ÷ ((1 + r)n − 1)
Here P is the amount financed, r is the monthly interest rate (your APR divided by 12 and by 100), and n is the number of months in the term. The formula produces a single fixed monthly payment that covers both interest and principal, so that the balance reaches exactly zero with your final payment. If your interest rate is 0% — as with some manufacturer promotions — the payment is simply the principal divided by the number of months.
The loan term is one of the biggest levers on your monthly payment. Stretching a loan over more months lowers the monthly amount, but it also means you pay interest for longer, so the total interest climbs. The table below shows the same $25,000 amount financed at a 6.5% APR across four common terms.
| Loan Term | Monthly Payment | Total Interest | Total of Payments |
|---|---|---|---|
| 36 months | $766 | $2,586 | $27,586 |
| 48 months | $593 | $3,470 | $28,470 |
| 60 months | $489 | $4,367 | $29,367 |
| 72 months | $420 | $5,276 | $30,276 |
Notice the pattern: moving from 36 to 72 months cuts the monthly payment by roughly $346, but more than doubles the total interest. The lower payment feels easier month to month, yet you hand the lender about $2,690 more over the life of the loan for the exact same car. This is the core trade-off every buyer faces, and the calculator lets you see the numbers for your own figures before you commit.
Your down payment and trade-in both reduce the amount you finance, and a smaller loan means a smaller payment and less interest. Because interest is charged on the balance, every dollar you put down up front saves you more than a dollar over the life of the loan. A down payment of 10% to 20% of the vehicle price is a widely used benchmark, and it also protects you from starting the loan already underwater.
A trade-in works much like a down payment, but with a bonus in most states: its value is subtracted from the taxable price before sales tax is calculated. On a $30,000 car with a $6,000 trade-in, a state that taxes the difference would only tax $24,000. That saves you both loan principal and tax. Combining a healthy down payment with a trade-in is the fastest way to shrink your monthly payment without touching the interest rate or the term.
People often use "APR" and "interest rate" interchangeably, but they are not always identical. The interest rate is the raw cost of borrowing the principal. The APR — annual percentage rate — can also fold in certain lender fees, which makes it a more complete measure of what the loan actually costs you. On many simple auto loans with no extra fees, the two numbers are essentially the same.
When you shop lenders, always compare APR to APR. A loan with a slightly lower interest rate but heavy origination fees can end up costing more than a loan with a marginally higher rate and no fees. This calculator treats the percentage you enter as the annual rate, converts it to a monthly rate, and uses that in the payment formula — so entering the APR quoted on a loan estimate gives you the most realistic payment.
Interest rates are almost always lower on new cars than on used cars. Lenders view new vehicles as lower risk because they have a predictable value and full manufacturer warranties, so they reserve their best advertised rates for them. Used cars, especially older ones with higher mileage, carry more risk and therefore higher rates. Your credit score, loan term, and down payment also move the rate you are offered.
Because the rate directly changes your payment and total interest, it pays to get pre-approved by a bank or credit union before visiting the dealer. That gives you a benchmark APR to compare against any dealer financing. You can plug both offers into this calculator to see, in dollars, which one truly costs less over your chosen term.
Sales tax on a vehicle can add thousands of dollars to the amount you finance, so it is worth understanding how it works. Most states charge sales tax on the vehicle price after subtracting the trade-in value, which is the method this calculator uses by default. A handful of states tax the full price regardless of trade-in, and a few states charge no vehicle sales tax at all. Rates also vary by county and city, so two buyers in the same state can face different totals.
When you finance, the sales tax is normally rolled into the loan rather than paid separately in cash. That means you pay interest on the tax as well as on the car, which is another reason a larger down payment helps — it offsets the extra balance that tax adds. Because rules and rates differ so widely, treat the tax figure from this calculator as a close estimate and confirm the exact rate with your dealer or state DMV before signing.
To get the most from the calculator, enter realistic numbers for every field. Start with the out-the-door vehicle price, add any down payment and trade-in you plan to use, enter your local sales tax rate, and use the APR from a real loan estimate rather than a rounded guess. Then try a few different terms to see how the monthly payment and total interest shift. The goal is to find the shortest term whose payment still fits comfortably in your monthly budget.
Used thoughtfully, an auto loan calculator turns an intimidating dealership negotiation into a set of clear numbers you control. You will know your target payment, understand how much a longer term really costs, and be able to spot when a deal is stretching your budget too far. Model your scenario, compare your options, and walk in prepared.
Getting a number is only useful if you know what to do with it. Here is what each line of your result is telling you and the decision it should inform:
When you run the numbers, the calculator also shows a short plain-language summary beneath your results that translates your specific inputs into what they mean for you — including a warning when a long term puts you at risk of going underwater.
Suppose you are buying a $32,000 vehicle. You have $4,000 for a down payment, a trade-in worth $3,000, your state charges 7% sales tax, you have been quoted a 6% APR, and you choose a 60-month term.
Reading that result: the trade-in helped twice — it shrank both the loan and the taxable price. Stretching the same loan to 84 months would lower the monthly payment but push total interest up sharply, which is exactly the trade-off the next section helps you weigh.
Once you have a payment estimate, use it to make a decision rather than just to satisfy curiosity. Which path fits depends on how the number compares to your budget:
A quick reference for the terms you will meet when financing a car:
In Canada, the tax on a vehicle depends on your province. You pay the harmonized sales tax (HST) in some provinces, and the federal goods and services tax (GST) plus a provincial sales tax in others; the Canada Revenue Agency explains which rate applies where. Rules for private sales and for vehicles bought in another province can be different, so check with your province before you buy.
When you trade in a vehicle at a dealer, the Canada Revenue Agency says the GST or HST is charged on the price minus the trade-in amount, as long as you are not selling the trade-in as a GST/HST registrant (a business). For example, on a $25,000 car with a $10,000 trade-in, GST or HST is charged on $15,000 (CRA: GST/HST and motor vehicles). Provincial sales tax rules for trade-ins can differ. This calculator also applies tax to the price minus the trade-in, so in Canada enter your province's combined rate in the Sales Tax field. The Sales Tax Calculator lists the GST, HST and provincial rates for every province, each checked against its official source.
The monthly payment uses the standard fixed-rate amortization formula, M = P × r × (1 + r)n ÷ ((1 + r)n − 1), where P is the amount financed, r is the monthly interest rate (APR ÷ 12 ÷ 100), and n is the number of months. Sales tax is applied to the vehicle price minus the trade-in value — the method most U.S. states use — and added to the amount financed along with any balance left after the down payment and trade-in. When the APR is 0%, the payment is simply the amount financed divided by the number of months. The calculator does not add title, registration, dealer add-ons, or lender fees, so real quotes may run slightly higher. All math runs in your browser and no inputs are stored or transmitted.
Formula and guidance last reviewed October 2026. Sales tax rules and interest rates vary by state and change frequently — verify current figures with your lender or dealer before making a decision. This tool is for planning and education, not financial advice.
Planning the whole picture? These free, private calculators pair naturally with your auto loan math:
Your monthly car payment is calculated from the amount you finance, your interest rate, and your loan term using a standard amortization formula. First, the calculator adds sales tax to the vehicle price and subtracts your down payment and trade-in value to find the amount financed. Then it applies the formula M = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the amount financed, r is the monthly interest rate (APR ÷ 12 ÷ 100), and n is the number of months. The result is a fixed monthly payment that pays off both principal and interest over the full term.
In most cases yes. When you finance a car, sales tax is typically rolled into the loan rather than paid separately in cash, so you pay interest on the tax as well. This calculator applies sales tax to the vehicle price minus your trade-in value, which is how most U.S. states assess car sales tax, and then adds that tax to the amount financed. Sales tax rules and rates vary by state, county, and city, so treat the tax figure as an estimate and confirm the exact rate with your dealer or state DMV.
A trade-in reduces your payment in two ways. First, its value is subtracted directly from the amount you finance, just like a down payment, which lowers your loan balance. Second, in most states the trade-in value is deducted from the taxable price before sales tax is calculated, so you also pay less tax. For example, on a $30,000 car with a $6,000 trade-in in a state that taxes the difference, you are only taxed on $24,000. A larger trade-in means a smaller loan, less interest, and a lower monthly payment.
Shorter terms such as 36 or 48 months carry higher monthly payments but far less total interest, and you build equity faster. Longer terms of 72 or 84 months lower the monthly payment but increase total interest and keep you in debt longer, often leaving you owing more than the car is worth. A common guideline is to choose the shortest term whose monthly payment fits comfortably in your budget. For many buyers, 48 to 60 months balances an affordable payment with reasonable total interest.
APR, or annual percentage rate, is the yearly cost of borrowing expressed as a percentage. On many simple auto loans the APR is very close to the stated interest rate, but APR can also fold in certain lender fees, giving you a fuller picture of the loan's true cost. When comparing offers, always compare APR to APR rather than interest rate to interest rate. This calculator treats the rate you enter as the annual rate and divides it by twelve to find the monthly rate used in the payment formula.
Yes. A larger down payment reduces the amount you finance, which lowers both your monthly payment and the total interest you pay over the life of the loan. Putting more money down also reduces the risk of becoming underwater, where you owe more than the car is worth, because you start with more equity. Many lenders recommend a down payment of at least 10 to 20 percent of the vehicle price. Even a few thousand extra dollars up front can noticeably cut your monthly payment.
Being underwater, also called having negative equity, means you owe more on your car loan than the vehicle is currently worth. Cars depreciate quickly, especially in the first few years, so a small down payment combined with a long loan term can leave your balance higher than the resale value for much of the loan. This becomes a problem if you want to sell or trade in the car, or if it is totaled in an accident, because the payout may not cover what you still owe. Larger down payments and shorter terms reduce this risk.
This calculator uses the same standard amortization formula that lenders use, so the monthly payment estimate is accurate for a fixed-rate loan with the figures you enter. Real quotes can differ slightly because of state-specific sales tax rules, title and registration fees, dealer add-ons, lender fees folded into APR, and rounding. Use the results to compare scenarios and set a budget, then confirm the exact numbers with your lender or dealer. This tool provides estimates for informational purposes and is not financial advice.
Use it to make a decision, not just to satisfy curiosity. Compare the monthly payment to your budget, remembering that insurance, fuel, and maintenance are extra costs on top of it. If the payment fits comfortably, test a shorter term to save on interest and build equity faster. If it is tight, put more money down, shop your rate with a credit union as well as the dealer, or look at a less expensive vehicle. Avoid stretching the term just to fit the payment, and add insurance and upkeep to the figure before you commit.
You go underwater when you owe more than the car is worth, which is most likely with a small down payment and a long term because cars depreciate quickly in the first few years. To avoid it, make a larger down payment — 10% to 20% of the price is a common benchmark — and choose the shortest term whose payment fits your budget rather than stretching to 72 or 84 months. A trade-in also helps by lowering the amount you finance from the start. If you may still be underwater early on, gap insurance can cover the difference if the car is totaled or stolen.
It depends on your province: you pay HST in some provinces, and GST plus a provincial sales tax in others. When you trade in a vehicle at a dealer, the Canada Revenue Agency says GST or HST is charged on the price minus the trade-in, as long as you are not selling the trade-in as a business. For example, on a $25,000 car with a $10,000 trade-in, GST or HST is charged on $15,000. Provincial rules for trade-ins and private sales can differ, so check with your province, and enter your province's combined rate in this calculator.
Rapid