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Auto & Personal Loan Calculator

Find your monthly payment and total interest, and compare loan terms side by side before you sign.

Free, no signup Runs in your browser — nothing stored Reviewed October 2026
Loan details
Loan type
$
%
$
$
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Loan term

Monthly payment

$636

60 months at 7% APR

Total interest

$6,037

Amount financed

$32,100

Includes $2,100 sales tax

Compare loan terms
36 months$991/mo · $3,582 interest
48 months$769/mo · $4,796 interest
60 months$636/mo · $6,037 interest
72 months$547/mo · $7,304 interest
84 months$484/mo · $8,596 interest
Balance by year
YearPrincipal paidInterest paidRemaining
1$5,556$2,071$26,544
2$5,958$1,669$20,585
3$6,389$1,239$14,197
4$6,851$777$7,346
5$7,346$282$0

How loan payments are calculated

Auto and personal loans are amortizing loans: every payment is the same, but early payments go mostly to interest and later payments mostly to principal. The payment formula is:

Payment = P × r ÷ (1 − (1 + r)−n)

where P is the amount financed, r is the APR divided by 12, and n is the number of months. For a car, the amount financed is the price plus sales tax, minus your down payment and trade-in.

The 20/4/10 rule for car loans

  • 20% down so you don't start the loan owing more than the car is worth.
  • 4 years (48 months) or less to limit interest and depreciation risk.
  • 10% of gross income or less for your total car costs, including insurance and gas.

Read how much car can I afford for price ranges by salary.

Ways to pay less interest

  • Improve your credit score first — see what credit score you need to buy a car.
  • Get pre-approved by a credit union or bank before visiting the dealer.
  • Choose the shortest term you can afford. The comparison above shows the trade-off.
  • Make extra payments toward principal if your loan has no prepayment penalty. The Debt Payoff Calculator shows how much faster you'll finish.

Frequently Asked Questions

At 7% APR, a $30,000 loan costs about $594 a month over 60 months, $718 over 48 months, or $511 over 72 months. Longer terms lower the payment but add interest — about $5,600 total at 60 months versus $6,800 at 72.
Usually. A 72- or 84-month loan lowers the monthly payment but costs more interest and makes it likely you'll owe more than the car is worth for years. Experts suggest 48 months or less — the 20/4/10 rule.
Your trade-in value reduces the amount you finance, and in most states it also reduces the price you pay sales tax on. If you still owe money on the trade-in, that balance is typically added to the new loan.
Scores of 661 and up generally get competitive rates, and 750+ gets the best. Below about 600, rates rise sharply, which can add thousands in interest. Getting pre-approved by a bank or credit union helps you compare against dealer financing.
Yes. Enter the amount you want to borrow as the price, set down payment, trade-in and sales tax to zero, and enter the APR and term from your loan offer.

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Disclaimer: This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice. Results depend on the numbers you enter and the assumptions described above. For decisions about your specific situation, consult a qualified professional.