If you have a car loan, the payoff question is simple: how long until it is gone, and how much interest will you pay before then? The answer depends on your balance, your interest rate and how much you pay each month. This car loan payoff calculator takes those three numbers and walks the loan forward one month at a time. Add an extra monthly payment and it shows how many months you cut off and how much interest you save.
How to use the car loan payoff calculator
- Enter your current loan balance — the principal still owed, shown on your latest statement.
- Enter the APR from your loan agreement.
- Enter your regular monthly payment (principal and interest only, without insurance or other add-ons).
- Enter an extra amount you could add each month. Leave it at 0 to see the payoff on the current plan only.
If your payment is no larger than the interest that builds up each month, the balance would never fall, and the calculator tells you so.
Payoff formula
Payment applied = regular payment + extra (capped at balance + interest)
New balance = balance + interest − payment applied
Repeat until the balance reaches 0
Closed form for months: n = −ln(1 − B × r ÷ P) ÷ ln(1 + r), with r = APR ÷ 1200
The calculator counts the months by repeating the monthly step, so the last payment is the smaller leftover amount. The closed form on the last line gives the same count before rounding up.
Worked example
You owe $20,000 at 6% APR and pay $450 a month.
- Monthly rate r = 0.005. First month's interest = 20,000 × 0.005 = $100, so $350 of the $450 reduces the balance.
- Repeating the step, the loan is paid off in 51 months with total interest of $2,675.06.
- Add $100 a month: each payment is $550, and the loan ends in 41 months with interest of $2,129.16.
- That is 10 months sooner and $545.90 less interest.
What an extra payment does
For a $20,000 balance at 6% APR and a $450 regular payment:
| Extra per month | Months to pay off | Total interest | Months saved | Interest saved |
|---|---|---|---|---|
| $0 | 51 | $2,675.06 | 0 | $0.00 |
| $50 | 45 | $2,370.33 | 6 | $304.73 |
| $100 | 41 | $2,129.16 | 10 | $545.90 |
| $200 | 34 | $1,771.68 | 17 | $903.38 |
| $300 | 29 | $1,519.14 | 22 | $1,155.92 |
Months to pay off at a $400 payment
At 6% APR with a $400 monthly payment:
| Balance | Months to pay off | Total interest |
|---|---|---|
| $5,000 | 13 | $176.03 |
| $10,000 | 27 | $709.37 |
| $15,000 | 42 | $1,652.87 |
| $20,000 | 58 | $3,072.27 |
| $30,000 | 95 | $7,694.39 |
Tips before you pay a loan off early
- Check for prepayment penalties. Most auto loans have none, but read your contract.
- Tell the lender the extra is for principal. Otherwise it may be held as an early payment toward next month.
- Compare with other uses of the money. Paying off a 6% loan earns a guaranteed 6% return; a card at 20% should usually come first.
- Consider a lower rate. If your credit has improved, the car refinance calculator shows whether a new loan would save more than extra payments.
To see how the original loan was set up, use the car payment calculator or the auto loan calculator.
Frequently asked questions
How do I pay off my car loan faster?
Pay more than the required amount each month and make sure the extra goes to principal. On a $20,000 balance at 6% with a $450 payment, adding $100 a month saves 10 months and about $546 of interest.
How is the payoff time calculated?
Each month the interest on the remaining balance is added, your payment is subtracted, and the process repeats until the balance is zero. The final payment is whatever is left.
Is the payoff amount the same as my balance?
Not exactly. A payoff quote from your lender includes interest accrued since your last payment and may include fees. Ask the lender for a payoff letter with a good-through date.
Why does the calculator say my payment is too low?
If the monthly payment is not larger than the monthly interest (balance × APR ÷ 1,200), the balance never falls. Raise the payment or check the rate.
Should I pay off my car loan early?
It saves interest at a guaranteed return equal to your APR. Compare that with higher-rate debt first, keep an emergency fund, and check your contract for prepayment penalties.