calculate-loan

01 Loan payments

Car Loan Estimated Payments: Calculate Monthly Costs

Calculator No. 01-6851 · Updated · Formula and assumptions shown below

Monthly payment $405.53
Total interest
$4,331.67
= Monthly payment × loan term × 12 − loan amount
Loan amount
$20,000
Input
Interest rate (APR)
8 %
Input
You enter
Loan amount ($), Interest rate (APR) (%), Loan term (years)
You get
Monthly payment ($), Total interest ($)
Rounding
2 dp

Estimate for education, not financial advice. The result follows from the numbers you enter and the formula shown. It is not a quote or an offer, and it does not include fees, taxes or insurance unless the calculator asks for them. Ask your lender for the exact figures.

This car loan payment calculator estimates your monthly payment and total interest from the amount financed, annual percentage rate (APR), and loan term. Enter the figures from a lender’s quote or use the defaults to see how fixed monthly payments are calculated.

Formula

The calculator uses the standard fixed-payment loan formula. It treats the APR as a nominal annual rate divided into monthly periods:

Monthly payment = P × r ÷ [1 − (1 + r)−n]

  • P is the amount borrowed, in dollars.
  • r is the monthly interest rate, calculated as APR ÷ 1,200. APR is entered as a percent per year.
  • n is the number of monthly payments, calculated as years × 12.
  • Total interest is monthly payment × number of payments − original loan amount, in dollars.

The displayed payment is rounded to cents. The total-interest result uses that displayed, rounded payment multiplied by the number of payments, then subtracts the principal. A lender’s actual payment schedule can differ slightly because of its rounding and payment-processing conventions.

Worked Example

Using the calculator’s default values—$20,000 financed, 8% APR, and a five-year term—the monthly rate is 8 ÷ 1,200, or 0.0066667, and the number of payments is 5 × 12, or 60.

Substitute these values into the payment formula:

$20,000 × 0.0066667 ÷ [1 − (1.0066667)−60] ≈ $405.53 per month.

Using the rounded monthly payment, total payments are $405.53 × 60 = $24,331.80. Subtracting the $20,000 loan amount gives estimated total interest of $4,331.80.

Assumptions

  • The APR and payment amount remain fixed for the full term.
  • Payments are made monthly, with the first payment one month after borrowing.
  • Interest is modelled monthly at APR ÷ 12, with monthly compounding.
  • The calculation excludes taxes, fees, insurance, optional products, and any down payment or trade-in unless those amounts are already reflected in the loan amount.

What the Payment Estimate Includes

A car payment estimate describes the loan portion of vehicle costs, not the full cost of owning or operating a car. The loan amount is the principal being financed. It may be different from the vehicle’s advertised price: a down payment or trade-in can reduce the amount financed, while eligible costs added to the loan can increase it. Use the amount on the proposed financing disclosure when you have one.

The APR is an annualized borrowing-cost figure expressed as a percentage. This calculator uses it as a fixed nominal rate and divides it by 12 to estimate monthly interest. It does not infer a rate from a credit profile or predict what a lender will offer. Enter the APR supplied in a quote; if you do not have one, the default is only an example input.

The term is the planned repayment duration. A longer term spreads repayment across more months, which can reduce the scheduled payment while increasing the total interest in this fixed-rate model. A shorter term means fewer payments, but the monthly payment is higher for the same principal and APR. The calculator illustrates this arithmetic; it does not determine whether a payment fits a person’s budget.

How to Use and Interpret the Estimate

  1. Enter the amount you expect to borrow, rather than automatically using the vehicle’s sticker price.
  2. Enter the APR shown in a lender’s quote as a percentage, such as 8 for 8%.
  3. Enter the loan term in years. The calculator converts it to monthly payments.
  4. Read the monthly payment and total-interest estimates together. The payment is a periodic amount; total interest is the modeled cost above the principal over the full term.

Compare estimates only when the principal, APR, and term assumptions match. For example, a payment from a shorter term should not be compared with one from a longer term as though only the lender or rate changed. If a quote includes a different amount financed, fees, or payment schedule, the figures are not directly equivalent.

Costs, Comparisons, and Common Mistakes

Vehicle expenses beyond the loan can include insurance, fuel or charging, maintenance, registration-related charges, and parking. Those are not calculated here. A monthly loan payment alone therefore is not a complete measure of transportation cost. Taxes and fees may also affect the amount financed depending on the transaction; use the actual financed principal to include them in the loan arithmetic.

  • Using the vehicle price as the loan amount: Down payments and trade-ins can change the principal, as can costs included in financing.
  • Entering 0.08 instead of 8 for an 8% APR: The rate field expects a percentage, not a decimal fraction.
  • Confusing APR with monthly interest: The formula converts annual APR to a monthly rate by dividing by 12, or 1,200 when the APR is entered as a whole-number percent.
  • Ignoring the term: Monthly payment and total interest depend on the number of monthly payments as well as the APR and principal.
  • Treating an estimate as a quote: Actual disclosures can include costs and details this calculator does not model.

This is a level-payment calculation. It does not model a changing interest rate, irregular payment dates, late or extra payments, a balloon payment, or a payoff before the scheduled end. If the loan terms include any of these, the simple estimate will not reproduce the full schedule.

Frequently Asked Questions

How much is a monthly payment on a $20,000 car loan?
It depends on the APR and term. With the calculator’s example inputs of 8% APR and five years, the estimated payment is $405.53 per month, excluding costs not included in the loan amount.

Does a car loan calculator include taxes and insurance?
No. This calculator estimates principal and interest only. Insurance is separate, and taxes or fees are included in the calculation only if they are already part of the amount financed you enter.

Why does a longer car loan term lower the monthly payment?
The principal is divided across more scheduled payments, so the payment can be lower. Interest also accrues over a longer modeled period, which can increase total interest for the same principal and APR.

Is APR the same as the monthly interest rate?
No. APR is entered as a yearly percentage here. The formula converts it to a monthly rate by dividing by 12; for example, 8% APR becomes approximately 0.6667% per month in this model.

Why does my lender’s payment differ from this estimate?
The quoted amount may use a different loan principal, APR, term, payment timing, rounding method, or costs. Check the lender’s itemized disclosure for the figures and assumptions used.

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 | $ | p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)) | 2
out int | Total interest | $ | pmt * yrs * 12 - 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.

More in this section

The whole Loan payments section →