A car loan total payment calculator estimates your monthly principal-and-interest payment and the total of those payments over the loan term. Enter the amount financed, APR, and term to see the payment and total interest; the figures exclude costs that are not part of the loan balance.
Formula
The calculator uses the standard fixed-payment loan formula. It first calculates the monthly payment, rounds that payment to the nearest cent, then multiplies the rounded amount by the number of monthly payments to get the total paid through scheduled installments.
- Monthly payment: M = round[P × r / (1 − (1 + r)−n), 2]
- Total of payments: T = M × n
- Total interest: I = T − P
Here, P is the loan amount in dollars, APR is the annual percentage rate entered as a percent, r = APR / 1200 is the monthly rate as a decimal, n is the term in months (years × 12), M is the monthly payment in dollars, T is the total scheduled payments in dollars, and I is the estimated interest in dollars. Rounding the monthly payment before calculating T means the displayed total matches the displayed payment multiplied by the number of installments.
Worked Example
Using the calculator’s default inputs: P = $20,000, APR = 8%, and term = 5 years.
- Convert the APR to a monthly rate: r = 8 / 1200 = 0.0066667.
- Convert the term to months: n = 5 × 12 = 60.
- Apply the payment formula: M = round[20,000 × 0.0066667 / (1 − (1.0066667)−60), 2] = $405.53.
- Calculate the scheduled total: T = $405.53 × 60 = $24,331.80.
- Subtract principal to estimate interest: I = $24,331.80 − $20,000 = $4,331.80.
The example results are a monthly payment of $405.53, total payments of $24,331.80, and total interest of $4,331.80.
Assumptions
- The interest rate is fixed for the entire loan term.
- Payments are equal monthly installments, paid at the end of each period.
- Interest is modelled monthly at APR divided by 12.
- The estimate excludes fees, taxes, insurance, optional products, and other amounts not included in the entered loan amount.
What the Total Payment Means
“Total payment” can mean different things in a car-buying conversation. In this calculator, total of payments means the sum of the scheduled monthly loan installments. It is not automatically the vehicle’s full ownership cost or the amount due at signing. The total includes repayment of the amount financed plus the interest produced by the formula.
The amount financed may differ from the vehicle’s advertised price. A down payment or trade-in value can reduce the amount borrowed, while items added to the loan balance can increase it. To estimate the loan itself, use the amount that will actually be financed, rather than assuming it equals the sticker price. Obtain the exact figures and any applicable charges from the seller or lender.
How to Use the Estimate
- Loan amount: Enter the principal being financed, in dollars. Do not enter a monthly payment here.
- APR: Enter the annual percentage rate supplied for the specific loan offer. The default is only an example, not a rate quote.
- Term: Enter the number of years. A five-year term is converted to 60 monthly payments.
- Compare like with like: When evaluating different hypothetical offers, use the same loan amount and compare the APR, term, payment, and total paid.
A smaller monthly payment does not necessarily mean a smaller total cost: extending the term increases the number of payments and may increase the total interest. Conversely, changing the amount financed or rate changes the payment as well. The calculator shows the arithmetic under the inputs provided; it does not determine eligibility, predict an offer, or establish what payment is manageable for a particular person.
Costs and Limits Not Included
This is a loan-payment estimate, not a complete vehicle budget. Insurance, fuel, maintenance, registration, and other ownership expenses are outside the formula. Taxes or fees are also not included unless they have already been incorporated into the amount financed. If a lender’s payment schedule includes a first payment date, a final payment that differs slightly, or charges paid separately, the actual cash flows can vary from this simplified estimate.
The formula assumes a fixed rate and level monthly installments. It does not model a changing rate, skipped or late payments, extra principal payments, a balloon payment, or a payoff before the scheduled end. Actual loan contracts may use precise daily interest calculations, specific payment dates, and rounding rules that differ from a basic monthly model. Use the lender’s written disclosure for contract-specific amounts.
Common Calculation Mistakes
- Mixing up APR and monthly rate: Enter APR as a yearly percentage, such as 8—not 0.08 or a monthly rate. The formula divides it by 1,200 to get a monthly decimal rate.
- Using the car price instead of the amount financed: The principal may change after a down payment, trade-in, or financed additions.
- Comparing different terms by payment alone: The payment does not show the full number of installments or total interest unless those are considered too.
- Expecting every lender figure to match exactly: Payment timing, daily interest, fees, and rounding can create differences from this estimate.
The APR input must be greater than zero for this payment formula. The calculation rounds each scheduled payment to cents and assumes that the rounded payment is made for every month; a real contract may adjust a final installment to account for accumulated rounding.
Frequently Asked Questions
How do I calculate the total paid on a car loan?
Calculate the monthly payment from the amount financed, APR, and term, then multiply that rounded payment by the number of monthly installments. Subtract the original principal from the total to estimate interest.
Does total payment include the down payment?
No. This calculator totals the scheduled loan installments only. Add any down payment or separate upfront costs yourself if you need to estimate a broader purchase outlay.
Is total interest the same as the total loan payment?
No. Total payments include repayment of principal and interest. Estimated interest is the total of installments minus the amount financed.
Why can a longer car loan have a lower monthly payment but cost more overall?
A longer term spreads repayment across more installments, which can lower each payment. It also means interest may accrue for a longer period, so compare the total payments as well as the monthly figure.
Why does my lender’s payment differ from this calculator?
The lender may include financed charges, use different payment dates or interest calculations, or adjust the final installment for rounding. Check the loan disclosure for the exact payment schedule.
This result is an estimate, and the lender’s disclosure gives the exact figures.
Related
Formula used
in p | Loan amount | $ | 20000 | 1 | 100000000 in apr | Interest rate (APR) | % | 8 | 0.01 | 100 in yrs | Loan term | years | 5 | 0.0833 | 50 out pmt | Monthly payment | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2 out tot | Total of payments | $ | pmt * yrs * 12 | 2 out int | Total interest | $ | tot - p | 2
Each line is one input (in, sel, list) or one result (out: label, unit, formula, decimals). How the calculators work
Method: the standard loan formula for this calculation, fixed rate and monthly compounding unless stated, rounded as each result states. Not financial advice; no lender, rate or product is recommended. See formulas and assumptions, the disclaimer or report an error.
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