Auto Loan Payoff Calculator
New payoff time, interest saved, and total paid from balance, rate, term, and extra.
What it does
Extra principal shortens a car loan the same way it shortens a mortgage: each added dollar skips its own future interest. On short auto terms the savings run smaller but the title arrives months sooner.
The tool above takes balance, APR, term, and monthly extra. It returns the new payoff time with interest saved and total paid beside them.
The default of $30,000 at 7% over 5 years with $100 extra pays off in 4 yr 2 mo instead of 5 yr 0 mo, saving $972.33 for $34,669.83 total. With zero extra the same loan costs $35,642.16.
The mechanics follow standard amortization math with auto finance guidance matching each term. Both treat extra as principal and warn that some contracts handle interest differently.
How to use
- Enter the current auto loan balance owed.
- Enter the APR and original term in years.
- Enter the monthly extra toward principal.
- Read the new payoff time first.
- Read interest saved to price the habit.
Formula
- base
- Scheduled amortizing payment at the contract APR.
- extra
- Added principal each month on top of base.
- saved
- Base total minus accelerated total.
Simple interest amortization like most bank and credit union loans; precomputed contracts rebate differently. Confirm extra applies to principal, not future installments.
Worked example
Example: $30,000 at 7%, $100 extra
Defaults: balance 30000, rate 7%, 5 years, extra 100.
- Base loan costs $35,642.16 over 60 months.
- Extra $100 joins principal every month.
- Simulation clears the balance in month 50: 4 yr 2 mo.
- Total paid drops to $34,669.83.
- Tool shows 4 yr 2 mo (was 5 yr 0 mo), $972.33 saved, $34,669.83 total.
Reference table
| Extra/mo | Payoff | Interest saved |
|---|---|---|
| $0 | 5 yr 0 mo | $0.00 |
| $50 | 4 yr 7 mo | $532.64 |
| $100 | 4 yr 2 mo | $972.33 |
Limits
- Simple interest assumed; precomputed loans differ.
- Insurance and fees ride outside the loan math.
- Underwater cars still owe the full balance at sale.
- Extra must be applied to principal by the lender.
Common mistakes
- Paying extra without confirming principal application.
- Stretching terms to 84 months for the payment.
- Rolling negative equity into the next loan.
- Skipping gap insurance while underwater.
- Raiding emergency funds to chase small savings.
Try it yourself
Quick checks. Answers sit tucked under each question.
$50 extra on the example?
4 yr 7 mo payoff, $532.64 saved ($35,109.52 total).
Zero extra?
No change: 5 yr 0 mo, $0.00 saved, $35,642.16 total.
Trade in while owing?
Owed minus value rolls into the next loan; extra now shrinks that gap.
Questions
How much does $100 extra save?
On the example: 10 months sooner and $972.33 less interest.
Where does extra go?
Tell the lender: principal. Otherwise it may prepay future installments.
Precomputed interest loans?
Some use rebate rules where extra helps less. Most bank loans amortize simply.
Extra or bigger down?
Bigger down borrows less from day one; extra rescues an existing loan.
Refinance instead?
Lower APR helps every payment; run the refinance math against extra here.
Pay car or invest?
Extra earns the APR risk free; investing may beat it with risk attached.