Automotive calculators

Car Purchase Calculator

Updated Aug 25, 2026 By Jehan Wadia
Rate Formulas
Vehicle & Trade-In
Optional — leave blank for $0.
Optional — leave blank for $0.
Optional — leave blank for $0.
Uses the same term, APR, down payment and trade-in above.
Financing Details
Typical range for Excellent credit (720+): 5.0% – 7.0%.
Updates the suggested APR range above. It never overwrites your APR.
Sets the payment dates in the amortization schedule.
Mo.
Applied at the payment number you enter.
Taxes & Fees
Rates vary by state, county and city — check your local rate.
Name it so it shows correctly in the results.
Most states tax price minus trade-in; a few tax the full price.
Turn off to pay taxes and fees in cash at signing.
Estimated Monthly Payment
$0.00
Principal & interest
Total Loan Amount (Amount Financed)
$0.00
After down payment, trade equity, rebate & fees
Total Interest Paid
$0.00
Over the life of the loan
Total Amount Paid (Payments)
$0.00
Monthly payment × months
Out-of-Pocket at Signing
$0.00
Down payment + unfinanced fees
Total Cost of Vehicle
$0.00
Cash at signing + all payments
Loan-to-Value Ratio (LTV)
0.00%
Good
Step-by-Step Solution
Cost Breakdown
Linear Breakdown & Balance Over Time
Loan Term Comparison — click a term to make it active
Metric
Affordability — How Much Car Can You Afford?
Maximum Vehicle Price
$0.00
Amortization Schedule & Early Payoff
New Payoff Date
Months Saved
0
Versus the scheduled term
Interest Saved
$0.00
From extra & lump-sum payments
Interest Actually Paid
$0.00
Schedule below
Total Cost of Ownership Estimator
Pick matching units: liquid efficiency with a liquid price, or electric efficiency with $/kWh.
5-Year Total Cost of Ownership
$0.00
Compare: Lease vs. Buy
≈ 6.00% APR equivalent.
Compared against the yearly distance you entered above.
Lease payments are taxed at the sales-tax rate entered in Taxes & Fees.
Measure Lease Buy (Finance)

Introduction

Buying a car costs more than the sticker price. This car purchase calculator shows you the full picture before you sign anything. Type in the vehicle price, your down payment, your trade-in, and the loan rate. You get your monthly car payment right away.

The tool also adds the parts people forget. Sales tax, title and registration fees, doc fees, and dealer fees all get counted. You can choose to roll them into the loan or pay them in cash at signing. If you owe more on your trade-in than it is worth, the calculator warns you and shows how that negative equity raises your payment.

You can do more than one thing here:

  • Compare loan terms from 24 to 84 months side by side
  • See a full month-by-month amortization schedule, and download it as a CSV file
  • Find out how much car you can afford from a target monthly payment
  • Add extra monthly payments or a lump sum to see how much interest you save
  • Estimate the total cost of ownership with gas or electricity, insurance, and repairs
  • Compare leasing against buying with real numbers

Every answer comes with a step-by-step math breakdown, so you can see exactly where each number came from. Change any input and the results update at once.

How to use our Car Purchase Calculator

Enter the car price, your down payment, trade-in details, loan term, rate, taxes and fees. The calculator shows your monthly car payment, total loan amount, total interest, cash due at signing, full amortization schedule, cost of ownership, and a lease vs. buy comparison.

Vehicle Price: Type the price you agreed to pay for the car, before tax and fees. You can also drag the slider. If you are still shopping, the car price calculator and the out-the-door price calculator help you set a realistic number.

Down Payment: Enter the cash you pay up front. Use the dollar box or the percent box — both stay in sync. See the down payment calculator to test different amounts.

Manufacturer Rebate / Incentive: Enter any cash rebate from the carmaker. It lowers the price before financing. Leave it at $0 if you have none.

Trade-In Value: Enter what the dealer will give you for your old car. Leave it at $0 if you are not trading one in. Not sure what it is worth? Check the trade-in value calculator or the used car value calculator.

Amount Owed on Trade-In: Enter the payoff still owed on your old car loan. If you owe more than the car is worth, the extra is added to your new loan. The auto loan payoff calculator can confirm your current balance.

Target Monthly Payment: Enter the payment you want to hit each month. The affordability panel uses it to show the highest car price you can afford.

Loan Term (months): Pick how long you will pay, from 24 to 84 months. Use the buttons, the dropdown, or the slider.

Annual Rate: Enter your interest rate. Then choose APR (normal car loan) or simple add-on interest, which costs more. Compare offers with the car loan interest rate calculator.

Credit Score Range: Pick your credit range. This only updates the suggested rate range. It never changes the rate you typed.

First Payment Date: Pick the date of your first payment. This sets the dates in the payment schedule.

Extra Monthly Payment: Enter any extra cash you will add to every payment. This pays the loan off sooner and cuts interest — see the extra payment calculator for more detail.

One-Time Lump Sum Payment: Enter a single big payment and the payment number when you will make it.

Sales Tax Rate: Enter your local sales tax rate. Rates change by state, county and city — look yours up with the sales tax calculator.

Title & Registration Fees: Enter what your state charges for the title and plates. The DMV fee calculator gives typical amounts.

Documentation Fee: Enter the dealer's paperwork fee.

Other Fee — Name and Amount: Name any extra charge, like dealer prep, and type the dollar amount.

Trade-in reduces the taxable amount: Turn this on if your state taxes the price minus your trade-in. Turn it off if your state taxes the full price.

Roll taxes & fees into the loan: Leave it on to finance taxes and fees. Turn it off to pay them in cash at signing.

Ownership Period (years): Enter how many years you plan to keep the car. This sets the cost of ownership total.

Annual Insurance: Enter what you pay for car insurance each year. The car insurance calculator can estimate this for you.

Annual Maintenance & Repairs: Enter what you expect to spend each year on oil changes, tires and repairs.

Annual Registration / Renewal Tax: Enter your yearly plate or renewal cost. Some drivers also owe a road tax.

Distance Driven per Year: Enter how far you drive in a year, then pick miles or kilometres. The mileage calculator helps if you are unsure.

Fuel / Energy Efficiency: Enter your gas mileage or EV efficiency, then pick the matching unit, like mpg, L/100 km or mi/kWh. The gas mileage calculator works out mpg from your last few fill-ups.

Fuel / Energy Price: Enter the price you pay for gas or power, then pick the matching unit. Gas units go with gas prices, and kWh goes with EV efficiency. See the fuel cost calculator for yearly totals.

Lease Term (months): Enter how many months the lease would run.

Money Factor: Enter the lease rate as a small decimal, like 0.00250. The calculator shows the matching APR.

Residual Value (%): Enter what the car is worth at lease end, as a percent of the price. The car depreciation calculator shows how fast value drops.

Acquisition Fee: Enter the fee the leasing company charges to start the lease.

Disposition Fee: Enter the fee charged when you turn the car back in.

Mileage Allowance: Enter how many miles or kilometres the lease lets you drive each year.

Excess Mileage Charge: Enter what you pay for each mile or kilometre over the limit.

Click Calculate to see your results, Reset to start over, or Print Summary to save a copy. You can also download the full payment schedule as a CSV file.

Buying a Car: What You Really Pay

The sticker price is only part of the cost. When you buy a car, you also pay sales tax, title and registration fees, a dealer document fee, and interest on your loan. Adding all of these together shows the true price of the car.

The Main Parts of a Car Deal

  • Vehicle price: the price you and the dealer agree on before tax and fees.
  • Down payment: cash you pay up front. A bigger down payment means a smaller loan and less interest.
  • Rebate: cash back from the carmaker. It lowers the price you finance.
  • Trade-in: what the dealer gives you for your old car. If you still owe money on it, that payoff is subtracted first. Run the numbers in the trade-in calculator.
  • Taxes and fees: sales tax plus title, registration, and dealer fees. You can pay these in cash or roll them into the loan.

How Car Loans Work

A car loan is paid back in equal monthly payments. Each payment covers some interest and some principal (the balance you owe). Early on, more of your money goes to interest. Later, more goes to principal. The auto loan calculator and the car loan amortization calculator show this split payment by payment.

APR is the yearly cost of borrowing. A lower APR means a lower payment. Your credit score matters a lot here: people with scores over 720 usually get the best rates, while lower scores pay much more. The APR calculator converts a quoted rate into the true yearly cost, and the car interest calculator totals what interest will cost you.

The loan term is how many months you pay. Common terms are 36, 48, 60, and 72 months. A longer term lowers your monthly payment but raises the total interest you pay. Short terms cost more each month but save you money overall. Buying used? The used car loan calculator uses the shorter terms and higher rates lenders apply to older vehicles.

Watch Out for Negative Equity

Negative equity happens when you owe more on your old car than it is worth. If you trade it in, that extra debt gets added to your new loan. You end up paying interest on a car you no longer drive, and your new loan starts out "underwater." If your current rate is high, an auto refinance may be cheaper than rolling the balance forward.

Loan-to-Value (LTV)

LTV compares your loan amount to the car's value. An LTV under 100% is healthy. Above 120% is risky, because if the car is totaled or stolen, insurance may not pay off the full loan. Gap insurance can help cover that gap. Use the LTV calculator to check the ratio on any deal.

Paying Extra Saves Money

Adding even a small amount to each payment goes straight to principal. That shortens the loan and cuts total interest. A one-time lump sum, like a tax refund, works the same way. Check that your lender has no prepayment penalty, then test your plan in the early payoff calculator.

Total Cost of Ownership

Your loan payment is not your only car cost. Each year you also pay for insurance, fuel or electricity, maintenance and repairs, and registration renewal. A cheap car with poor gas mileage and high insurance can cost more than a pricier car that sips fuel. Looking at cost per mile gives you a fair way to compare cars, and the fuel consumption calculator sharpens your energy estimate.

Lease vs. Buy

When you lease, you pay for the car's drop in value during the lease, plus a finance charge based on the money factor (multiply it by 2400 to get a rough APR). Leases have lower monthly payments, but you own nothing at the end and you pay fees for extra miles and turn-in. When you buy, payments are higher, but the car is yours once the loan ends. Buying usually costs less over many years. Leasing can make sense if you want a new car every few years and drive few miles. Dig into the lease side with the lease calculator.

Tips Before You Sign

  • Negotiate the car price first, not the monthly payment.
  • Get a loan offer from your own bank or credit union to compare with the dealer's — the loan comparison calculator lines them up side by side.
  • Aim for at least 20% down on a new car and a term of 60 months or less.
  • Check that the payment fits your budget by reviewing your debt-to-income ratio and your monthly budget.
  • Ask for a full out-the-door price in writing, with every fee listed.
  • Check your local sales tax rules — most states tax the price minus your trade-in, which saves you money.

Formulas used

Amount financed (loan principal)
P = \left(\text{Price} - \text{Rebate}\right) + F_{\text{financed}} - D - \left(T_{\text{value}} - T_{\text{owed}}\right)
Sales tax and total taxes & fees
\text{Tax} = \frac{t}{100}\times\text{TaxBase},\quad \text{TaxBase} = \begin{cases}\text{Price}-\text{Rebate}-T_{\text{value}} & \text{trade credit}\\ \text{Price}-\text{Rebate} & \text{otherwise}\end{cases}
Monthly payment (amortized APR loan)
M = P\cdot\frac{i\left(1+i\right)^{n}}{\left(1+i\right)^{n}-1},\quad i = \frac{\text{APR}}{1200}
Simple / add-on interest payment
I = P\cdot\frac{\text{APR}}{100}\cdot\frac{n}{12},\qquad M = \frac{P+I}{n}
Total interest, total cost and loan-to-value
I = M\cdot n - P,\qquad \text{TotalCost} = \left(D + F_{\text{unfinanced}}\right) + M\cdot n,\qquad LTV = \frac{P}{\text{Price}}\times 100\%
Amortization step (per payment)
\text{Int}_k = B_{k-1}\cdot i,\quad \text{Prin}_k = \left(M + E + L_k\right) - \text{Int}_k,\quad B_k = B_{k-1} - \text{Prin}_k
Maximum affordable price from a target payment
P_{\max} = M_{\text{target}}\cdot\frac{1-\left(1+i\right)^{-n}}{i},\qquad \text{Price}_{\max} = \frac{P_{\max} + R\left(1+\tau\right) + \tau\,T_{\text{value}} - F + D + T_{\text{value}} - T_{\text{owed}}}{1+\tau}
Lease monthly payment
M_{\text{lease}} = \left(\frac{C_{\text{adj}} - V_{\text{res}}}{n_{L}} + \left(C_{\text{adj}} + V_{\text{res}}\right)\cdot MF\right)\left(1+\frac{t}{100}\right)

Frequently asked questions

Why is my payment here different from the dealer's quote?

Dealers often add things this tool does not know about, such as an extended warranty, gap insurance, paint protection, or a different fee list. Their tax rate or APR may also differ.

Ask the dealer for the out-the-door price with every fee listed, then type those exact numbers in here. The results should then match closely.

What does Amount Financed mean?

It is the money you actually borrow. The calculator works it out like this:

  • Car price minus rebate
  • Plus taxes and fees, if you roll them into the loan
  • Minus your down payment
  • Minus your trade-in value, plus anything you still owe on it

Your monthly payment is based on this number, not the sticker price.

Should I roll taxes and fees into the loan or pay cash?

Paying cash costs less. If you finance taxes and fees, you pay interest on them for the whole term.

Rolling them in helps if you need to keep cash on hand. Flip the switch both ways and compare the Total Cost of Vehicle to see the real difference.

Why is my Total Cost of Vehicle higher than my Total Amount Paid?

Total Amount Paid is only your monthly payments added up.

Total Cost of Vehicle adds the cash you hand over at signing, which is your down payment plus any taxes and fees you did not finance. That is why it is the bigger number.

Should I pick APR or simple add-on interest?

Pick APR. Almost every car loan in the US uses APR, where interest is charged on the balance you still owe. As you pay down the loan, the interest shrinks.

Simple add-on interest charges you on the full starting amount for the whole term, so it costs more. Some buy-here-pay-here lots use it. Only choose it if your contract says so.

Why does the tool show $0 interest saved when I add extra payments?

That happens when you pick simple add-on interest. With that kind of loan the total interest is locked in at the start, so paying early does not lower it.

Switch the rate type to APR and extra payments will cut both months and interest.

How does the affordability panel figure out my max car price?

It works backward. It takes your target monthly payment, your term, and your APR to find the biggest loan those payments can cover.

Then it adds back your down payment and trade-in equity, and subtracts taxes and fees, to show the highest sticker price you can handle.

Does the calculator include gap insurance or an extended warranty?

Not by default. If you want them counted, type the cost into the Other Fee box and name it, such as "Gap insurance." It will then be added to your deal and financed if you have that switch on.

Can I use this for a used car?

Yes. The math is the same. Just remember that used-car loans often have higher rates and shorter terms, so raise the APR and pick a shorter term to get a realistic result.

What should I put for a down payment?

A common rule is 20% down on a new car and 10% on a used one. Use the percent box to set it fast.

More money down means a smaller loan, a lower payment, less interest, and a safer LTV.

My LTV is over 100%. Is that bad?

It means you owe more than the car is worth. This is common with a small down payment, rolled-in fees, or negative equity from a trade-in.

If the car is wrecked or stolen, insurance pays only what the car is worth, so you could still owe money. Gap insurance or a bigger down payment fixes that risk.

Does the first payment date change how much I pay?

No. It only sets the dates shown in the payment schedule and your payoff date. Your payment amount and total interest stay the same.

Why does my payment schedule end before the last month of my term?

Because your extra monthly payment or lump sum paid the loan off early. The table stops on the month the balance hits zero.

The Months Saved and Interest Saved boxes show how much you gained.

Can I compare an electric car to a gas car?

Yes. In the ownership section pick an electric efficiency unit like mi/kWh, and set the price unit to $/kWh. For a gas car use mpg with $/gal.

The units must match, liquid with liquid or electric with electric, or the fuel cost shows as $0.

Can I use this outside the United States?

Yes. The math works with any currency, just read the $ as your own money. You can also switch the distance boxes to kilometres and use L/100 km or km/L for fuel use.

Is my information saved or shared?

No. Everything is worked out in your browser. Nothing is sent anywhere or stored. Use the Print Summary button or the CSV download if you want a copy.

Is the dealer doc fee negotiable?

Sometimes. Many states cap it, and some dealers will not remove it at all. If they will not drop it, ask for the same amount off the car price instead.

Type whatever amount they charge into the Documentation Fee box so your true cost shows up.

Why does a longer term look cheaper each month but cost more overall?

You spread the same debt over more months, so each payment is smaller. But you also pay interest for more years.

Look at the Loan Term Comparison table. The monthly payment drops as the term grows, while total interest climbs.

What if I have no trade-in or no rebate?

Leave those boxes at $0. The calculator just skips them and figures your loan from the price, down payment, taxes, and fees.

Why is the lease payment lower but the lease still costs more?

Lease payments only cover the value the car loses while you drive it, so they are small. But at the end you own nothing, and you may owe a disposition fee and extra mileage charges.

When you buy, you keep a car with real value. The comparison table subtracts that value to show the fair net cost of each choice.