Negative Equity Car Loan Calculator
Work out your equity, the new loan amount and what rolling negative equity into a new car loan really costs.
Negative Equity Car Loan Calculator
Your current car
The new car
If your car is worth $12,000 and you owe $16,000, you have $4,000 of negative equity. Rolling it into a $28,000 car with $2,000 down, 6% sales tax and $500 in fees makes the new loan $32,180, or 115% of the car’s price. At 7.5% over 72 months the payment is about $556.40 a month, which is $69.16 more than it would be without the old debt, or about $4,980 extra over the loan.
How to use this negative equity car loan calculator
- Enter your car’s trade-in value and the loan payoff amount.
- Enter the new car price, your cash down payment, sales tax and fees.
- Enter the loan APR and term in months.
- Read your equity, the new loan, the payment and the extra cost of any negative equity rolled in.
The math behind the result
Equity = trade-in value − loan payoff. A negative number is negative equity (being upside down).
New loan = price × (1 + sales tax) + fees − down payment + negative equity. Positive equity is subtracted instead, because it acts like a down payment. The monthly payment uses the standard loan formula, and the extra cost compares the payment with and without the rolled-in amount.
Worked example
Trade-in $12,000, payoff $16,000, new car $28,000, $2,000 down, 6% tax, $500 fees, 7.5% for 72 months:
- Equity: −$4,000
- New loan: $32,180 (115% of the price); without the old debt it would be $28,180
- Payment: $556.40 a month vs $487.24, so $69.16 more
- Extra paid over 72 months because of the rolled-in debt: about $4,980 (the $4,000 plus about $980 of interest)
What negative equity means
You have negative equity, also called being upside down or underwater, when you owe more on the loan than the car is worth. Cars lose value fastest in the first years, while a long loan with a small down payment pays down the balance slowly, so the gap is common.
What happens if you roll it into a new loan
The old balance is added to the new loan. You pay interest on it again, and you start the new loan owing more than the new car is worth, so you are underwater from day one. Many lenders also limit how much they will lend compared with the car’s value, so a large gap can get a trade-in declined or push the rate up.
Ways to shrink the gap
Pay extra toward the principal, put cash toward the shortfall at the dealer, wait while the loan balance falls faster than the car’s value, or sell the car yourself, since private buyers often pay more than a dealer’s trade-in offer. Our loan payoff calculator shows how much extra payments save.
Positive equity works in your favor
If the car is worth more than you owe, the difference reduces what you borrow. Enter a higher trade-in value than the payoff and the calculator subtracts the equity from the new loan.
Key terms
- Negative equity
- Owing more on a loan than the asset is worth.
- Payoff amount
- The exact figure needed to close the loan today, from your lender.
- Loan-to-value (LTV)
- The loan amount as a percentage of the car’s value or price.
- GAP insurance
- Coverage that pays the difference between what you owe and the car’s value if it is totaled or stolen.
Frequently asked questions
How do I calculate negative equity on a car?
Subtract the loan payoff amount from the car’s trade-in value. If the result is negative, that is your negative equity.
Can I trade in a car with negative equity?
Usually yes, but the dealer adds the shortfall to the new loan unless you pay it in cash. That raises the loan amount, the payment and the interest you pay.
Is it a bad idea to roll negative equity into a new loan?
It is expensive because you borrow and pay interest on the old balance, and you start the new loan underwater. It can be worth it only when the new loan is cheaper overall and you can afford the higher payment.
Does GAP insurance cover negative equity on a trade-in?
No. GAP covers the shortfall if the car is totaled or stolen, not the shortfall when you trade it in.
How much do cars depreciate?
New cars commonly lose a large share of their value in the first year, often around 20%, then continue to lose value each year. Actual figures vary a lot by model.
Sources and further reading
Related calculators
Related guides
Figures in the examples are illustrative and use the inputs shown. Market rates and program rules change; confirm current terms with your lender or the linked official sources before making a decision.
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Understanding loan payments and interest is foundational to smart borrowing. Whether you are financing a home, car, or personal expense, knowing your true cost helps you negotiate better rates and pay off debt faster. Always compare the APR -- not just the interest rate -- to understand the total cost.
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Built by Abdul Rahman · Last reviewed: · Report an error
Disclaimer: This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice. Results depend on the figures you enter and on simplified assumptions; actual rates, taxes, and outcomes will differ. Consult a qualified professional before making financial decisions.