Short answer: on a $30,000 car loan at 7% for 60 months, paying an extra $100 a month raises your payment from $594.04 to $694.04 and cuts total interest from $5,642.12 to $4,669.80. That is $972.32 in interest saved, and the loan is paid off in 50 payments instead of 60, 10 months sooner.
Why extra payments save money: Auto loans usually charge interest each month on the balance you still owe. When an extra payment goes straight to principal, that balance shrinks faster, so each later month charges less interest and more of every regular payment pays down the loan. The loan ends sooner, and you pay less interest in total.
Use the car loan payoff calculator below to enter your own loan amount, APR, term, and extra monthly payment and see the interest saved, time saved, new payoff date, and full payment schedule.
All figures are estimates for a fixed-rate, simple-interest loan with no fees or prepayment penalty, with every extra dollar applied to principal. Your lender's numbers may differ. This is not financial advice.
How to use this calculator
Enter your loan details. Enter your loan amount, APR, loan term, and extra monthly payment using the slider or the number box for each field. The results update as you type.
Read the KPI cards. Check the KPI cards for your estimated interest saved, time saved, and new payoff date compared with paying only the regular amount.
Expand the payment schedule. Open the payment schedule to see how each payment splits between interest and principal and how the balance falls with and without the extra amount.
Check with your lender. Before you pay extra, confirm with your lender that extra payments go to principal and that your loan has no prepayment penalty.
Car Loan Payoff Calculator with Extra Payments
See how much interest and time you could save by adding a little extra to your car payment each month.
Interest saved
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Time saved
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New payoff date
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Original payoff: –
Regular monthly payment
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New monthly payment
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Total interest · without extra
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Original schedule
Total interest · with extra
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New schedule
Total paid · with extra
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Without extra: –
Amortization schedule
Estimates only, not financial advice. Assumes a simple-interest loan with no fees and no prepayment penalty, and that your lender applies the extra amount to principal. Confirm both with your lender before paying extra.
Next step: ask your lender whether extra payments go straight to principal and whether there is a prepayment fee. The guide below covers what to check.
How extra car loan payments work
Most auto loans are simple-interest loans. Each month, interest is charged on the balance you still owe, and the rest of your payment reduces that balance. When you pay more than the required amount and the lender applies the extra to principal, the balance drops faster. Every later month then charges interest on a smaller balance, so more of each regular payment goes to principal and the loan ends early.
The effect builds over time. An extra payment made early in the loan saves more than the same amount paid near the end, because it stops interest from being charged on that money for more months.
Worked examples
These loans were run through this calculator, with the extra amount added to every monthly payment from the first payment.
Estimated savings from extra monthly payments (simple-interest loan, no fees)
Loan
Extra per month
Payment
Total interest
Interest saved
Time saved
$30,000 at 7%, 60 months
$100.00
$594.04 → $694.04
$5,642.12 → $4,669.80
$972.32
10 months
$25,000 at 6.5%, 72 months
$50.00
$420.25 → $470.25
$5,257.82 → $4,565.20
$692.62
9 months
$40,000 at 8%, 60 months
$200.00
$811.06 → $1,011.06
$8,663.35 → $6,590.58
$2,072.77
13 months
$20,000 at 5%, 48 months
$100.00
$460.59 → $560.59
$2,108.09 → $1,697.86
$410.23
9 months
How much difference the extra amount makes
For the same $30,000 loan at 7% for 60 months:
Interest saved by extra amount ($30,000, 7%, 60 months)
Extra per month
New payment
Payments
Interest saved
Time saved
$50.00
$644.04
55
$532.68
5 months
$100.00
$694.04
50
$972.32
10 months
$200.00
$794.04
43
$1,653.71
17 months
Higher rates, larger balances, longer terms, and bigger extra amounts all increase the savings. Short, low-rate loans carry less interest to begin with, so the dollar savings are smaller. Run your own numbers in the calculator above.
Make sure the extra goes to principal
The savings above assume your lender applies every extra dollar to principal right away. Not all lenders do this automatically. Some treat extra money as an early payment toward next month's bill, which moves your due date forward but may not reduce the interest you pay. To avoid that:
Look for a "principal only" or "additional principal" option when you pay online.
Make the extra amount a separate payment if your lender allows it.
Check your next statement to confirm the principal balance dropped by the extra amount.
If anything is unclear, call your lender and ask how extra payments are applied.
Who paying extra fits, and who should wait
It may fit you if
You have an emergency fund and no higher-interest debt.
You plan to keep the car until the loan is paid off.
Your loan uses simple interest and has no prepayment penalty.
You want a lower total cost and to own the car outright sooner.
Consider waiting, or another option, if
You carry credit card or other higher-interest debt. Paying that down first usually saves more.
Your savings are thin. Money paid into a car loan is hard to get back if you need it.
Your loan has a prepayment penalty or uses precomputed interest. Paying early may save less than this calculator shows. Check your contract.
Your rate is high. Refinancing to a lower rate may help more, as long as fees and a longer term don't raise your total cost. You can also refinance and still pay extra.
Common pitfalls
Extra money held as a future payment. If the lender applies it to next month instead of principal, you may not save interest.
Skipping required payments. Paying extra does not usually let you skip a payment unless your lender confirms it in writing.
Forgetting add-ons. GAP coverage, warranties, taxes, and fees are not part of these estimates.
Stretching your budget too far. A smaller extra amount you can keep paying is better than a large one you have to stop.
Methodology and assumptions
All results on this page are estimates from the calculator's own code, using these assumptions:
Loan type: fixed-rate, simple-interest auto loan. Monthly interest is the balance × APR ÷ 12, rounded to the cent.
Regular payment: the standard amortized payment, rounded to the cent.
Extra payment: added to every monthly payment from the first payment and applied entirely to principal.
Final payment: capped at the remaining balance plus interest, so it is usually smaller than the others.
Not included: fees, prepayment penalties, GAP, warranties, and taxes. All payments are assumed to be on time.
Savings: interest saved is total interest without the extra minus total interest with it. Time saved is the difference in the number of payments.
Dates: payoff dates in the calculator depend on the first payment date it assumes (the first of next month) and shift if you change it; dollar amounts do not. The KPI cards round to whole dollars, so $972.32 shows as $972.
Your lender's figures may differ because of its payment posting rules, day-count method, and fees. Treat these results as a planning estimate for a simple-interest loan with no fees, not a quote or financial advice.
Car loan payoff FAQ
How much does paying an extra $100 a month on a car loan save?
On a $30,000 loan at 7% for 60 months, paying an extra $100 a month saves an estimated $972.32 in interest and pays the loan off in 50 payments instead of 60, which is 10 months sooner. On a $20,000 loan at 5% for 48 months, the same extra $100 saves an estimated $410.23 and 9 months. These estimates assume a simple-interest loan with no fees and every extra dollar applied to principal.
Does paying extra on a car loan lower the monthly payment?
Usually not. On most simple-interest auto loans the required payment stays the same and the extra money shortens the loan instead. On a $30,000 loan at 7% for 60 months, the regular payment stays $594.04, and adding $100 a month ends the loan after 50 payments instead of 60. Some lenders treat extra money as paying ahead on future bills instead, so ask how yours applies it.
How much does an extra $50 or $200 a month save on a car loan?
On a $30,000 loan at 7% for 60 months, an extra $50 a month saves an estimated $532.68 in interest and 5 months, while an extra $200 saves $1,653.71 and 17 months, compared with $972.32 and 10 months for an extra $100. Each added dollar still saves interest, but the saving per dollar gets a little smaller as the loan gets shorter.
Does an extra car payment go to principal?
Not always. Some lenders apply extra money to principal right away, while others treat it as an early payment toward your next bill, which may not reduce the interest you pay. This calculator assumes every extra dollar goes to principal, so check how your lender handles it.
How do I make sure my extra payment goes to principal?
Choose a "principal only" or "additional principal" option when you pay, or make the extra amount a separate payment if your lender allows it. Then check your next statement to confirm the principal balance dropped by the extra amount, and call your lender if it did not.
Is there a prepayment penalty for paying off a car loan early?
Many simple-interest auto loans have no prepayment penalty, but some loans do, and loans that use precomputed interest may save you less when you pay early. Check your loan contract or ask your lender before you start paying extra. This calculator does not include any penalties or fees.
Does paying off a car loan early help or hurt your credit score?
It can go either way, usually by a small amount. Your record of on-time payments stays on your credit report after the loan is closed, but closing an installment loan can change your mix of credit and may lower your score a little for a while, especially if it was your only installment account. Any score change depends on your whole credit profile, and this calculator does not estimate it.
Is it better to pay bi-weekly or add extra each month?
Both work by paying more principal sooner. A bi-weekly plan adds the equivalent of one extra monthly payment each year, while a fixed extra amount each month lets you choose exactly how much to add. Some bi-weekly programs charge fees or hold payments, so a simple extra monthly amount is often easier to control.
Is it better to pay extra on my car loan or invest the money?
It depends on your loan rate, your other debts, your emergency savings, and your goals. Paying extra gives a predictable saving equal to the interest you avoid, while investing may earn more or less over time. This calculator shows the interest side only and is not financial advice.
Should I refinance my car loan instead of paying extra?
Refinancing to a lower rate can reduce interest, but fees or a longer term can raise your total cost, so compare the total you would pay under each option. You can also refinance and keep paying extra. Offers, terms, and approval vary by lender.