Car Loan Payoff Calculator: Months & Interest 2026

How car loan payoff is worked out

A car loan payoff is worked out month by month: the monthly rate is the APR divided by 12, the month’s interest is the balance times that rate, the payment covers the interest first and then the balance, and the balance is simulated until it reaches zero. The last payment is just the balance plus that month’s interest, so it is smaller than the usual payment. The total interest is the sum of the monthly interest, and the total paid is the balance plus the total interest.

At the defaults — $25,000 balance, 7.5% APR, $500 a month — the first month’s interest is $25,000 × 7.5% ÷ 12 = $156.25, so $343.75 of the $500 payment touches the balance. The balance falls month by month, and after 61 months (5 yr 1 mo) it reaches zero, having cost $5,069.24 of interest and $30,069.24 in all. The last payment is $69.24. The standard 60-month plan is $500.95 a month with $5,056.91 of interest, so paying $500 a month costs $12.33 more interest and 1 extra month against it.

The worked example, line by line

Setup: $25,000 balance, 7.5% APR, $500 a month.

Line 1 — the monthly rate. 7.5% ÷ 12 = 0.625% a month.

Line 2 — the first month’s interest. $25,000 × 7.5% ÷ 12 = $156.25 of interest in month 1.

Line 3 — the balance after month 1. $25,000 + $156.25 − $500.00 = $24,656.25. Only $343.75 of the payment touched the balance.

Line 4 — the long run. Each month the interest shrinks with the balance, so more of the $500 payment reaches the balance. Month after month, the loan takes 61 months (5 yr 1 mo) to reach zero.

Line 5 — the totals. The interest over all 61 months is $5,069.24, the total paid is $25,000 + $5,069.24 = $30,069.24, and the last payment is $69.24.

Reverse: a $777.66 a month payment clears the loan in 36 months; $604.48 in 48 months; $500.95 in 60 months; and $432.26 in 72 months. At $500 a month, the biggest balance gone in 60 months is $24,952.65, and in 48 months it is $20,679.19. Any balance at or above $80,000 never pays off at $500 a month and 7.5% APR.

Every branch, checked

$20,000 balance: the first month’s interest is $20,000 × 7.5% ÷ 12 = $125.00, so $375.00 of the $500 payment touches the balance. It takes 47 months (3 yr 11 mo), with $3,086.63 of interest and $23,086.63 paid in all. A $5,000 smaller balance takes 14 fewer months, because more of every payment reaches the balance.

$30,000 balance: the first month’s interest is $30,000 × 7.5% ÷ 12 = $187.50, so $312.50 of the $500 payment touches the balance. It takes 76 months (6 yr 4 mo), with $7,718.05 of interest and $37,718.05 paid in all. A $5,000 bigger balance takes 15 more months, and costs $2,648.81 more interest.

$15,000 balance: the first month’s interest is $15,000 × 7.5% ÷ 12 = $93.75, so $406.25 of the $500 payment touches the balance. It takes 34 months (2 yr 10 mo), with $1,663.35 of interest and $16,663.35 paid in all. A smaller balance pays off fast, because most of every payment reaches the balance.

APR 5%: the first month’s interest is $25,000 × 5% ÷ 12 = $104.17, so $395.83 of the $500 payment touches the balance. It takes 57 months (4 yr 9 mo), with $3,092.30 of interest and $28,092.30 paid in all. A lower APR saves $1,976.94 of interest, and 4 months.

APR 10%: the first month’s interest is $25,000 × 10% ÷ 12 = $208.33, so $291.67 of the $500 payment touches the balance. It takes 65 months (5 yr 5 mo), with $7,474.45 of interest and $32,474.45 paid in all. A higher APR costs $2,405.21 more interest, and 4 more months.

APR 3%: the first month’s interest is $25,000 × 3% ÷ 12 = $62.50, so $437.50 of the $500 payment touches the balance. It takes 54 months (4 yr 6 mo), with $1,739.80 of interest and $26,739.80 paid in all. At 3% the loan costs barely more than a fifteenth of the balance in interest.

Payment $600 a month: the first month’s interest is still $156.25, so $443.75 of the $600 payment touches the balance. It takes 49 months (4 yr 1 mo), with $4,051.02 of interest and $29,051.02 paid in all. Paying $100 more a month saves 12 months and $1,018.22 of interest against the default.

Payment $400 a month: the first month’s interest is still $156.25, so $243.75 of the $400 payment touches the balance. It takes 80 months (6 yr 8 mo), with $6,799.84 of interest and $31,799.84 paid in all. Paying $100 less a month costs 19 more months and $1,730.60 more interest.

Payment $750 a month: the first month’s interest is still $156.25, so $593.75 of the $750 payment touches the balance. It takes 38 months (3 yr 2 mo), with $3,121.88 of interest and $28,121.88 paid in all. Paying $250 more a month saves 23 months and $1,947.36 of interest against the default.

Payment $450 a month: the first month’s interest is still $156.25, so $293.75 of the $450 payment touches the balance. It takes 69 months (5 yr 9 mo), with $5,805.55 of interest and $30,805.55 paid in all. Fifty dollars less a month costs 8 more months and $736.31 more interest.

Reverse — the payments for a payoff date: a $777.66 a month payment clears the $25,000 loan in 36 months; $604.48 a month clears it in 48 months; $500.95 a month clears it in 60 months (the standard 60-month plan); and $432.26 a month clears it in 72 months. At $500 a month, the biggest balance gone in 60 months is $24,952.65, and in 48 months it is $20,679.19. Each reverse payment is rounded up to the cent: one cent less takes one month longer.

Never-payoff threshold: at $500 a month and 7.5% APR, any balance at or above $80,000 never pays off, because the first month’s interest alone is $500.00 or more. At $80,000 the first month’s interest is exactly $500.00, so nothing touches the balance; above it, the balance grows every month.

Edge — 0% APR: with no interest, every dollar of the payment touches the balance, so $25,000 at $500 a month takes exactly 50 months and costs $0 of interest.

What the defaults assume

The model assumes a fixed APR, no new charges, no fees, and the same payment every month, so the balance only moves by the interest and the payment. It assumes the payment is applied to the interest first and then the balance, and it simulates month by month with unrounded running values, rounding only for display. It leaves out dealer fees, gap insurance, trade-in value, late charges and extra payments that are not applied to principal, which change the payoff in real life. Rounding convention: money is rounded to cents, months are whole numbers, and all figures are computed from unrounded values, rounded only for display.

Output · formula · meaning

Who uses this

• The buyer with a $25,000 loan: they learn $500 a month takes 61 months and costs $5,069.24 of interest — so they know the loan is a 5-year plan, and they check the $600 a month case at 49 months before paying the minimum again.
• The buyer with a small balance: they learn a $15,000 balance takes 34 months and costs $1,663.35 of interest — so they know a smaller balance pays off fast, and they check the $20,000 case at 47 months before borrowing more.
• The buyer on a tight budget: they learn $400 a month takes 80 months and costs $6,799.84 of interest — so they know a small payment costs $1,730.60 more interest, and they check the $80,000 never-payoff threshold before cutting the payment.
• The buyer picking a payoff date: they learn $777.66 a month clears the loan in 3 years, and $432.26 a month takes 6 years — so they know the payment for the date they want, and they check the $24,952.65 maximum balance for 5 years at $500 a month before setting the amount.

Accuracy & limitations

The math is exact for the numbers you enter: the monthly interest is the balance times the APR divided by 12, the payment covers the interest first and then the balance, and the balance is simulated month by month with unrounded running values until it reaches zero. What the model cannot do is read your lender’s statement for you: check the APR and the balance on the statement, because a 10% APR and a 3% APR give very different answers. It assumes a fixed APR, no fees, no dealer charges, and the same payment every month, and it leaves out gap insurance, trade-in value and late charges. For paying the loan off early, see how to pay off a car loan early; for the payoff plan on any loan, see loan payoff calculator.