Negative Equity Trade-In Calculator
The old loan, the next car, and the months in between
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Educational estimate only. Confirm the assumptions, current rules, fees, and rounding that apply to your situation before making a decision.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter what the dealer will give for your current car and the payoff figure from your lender. The gap between the two is what gets rolled forward.
- 02
Enter the rate and the months left on your current loan, so the page can work out how long waiting would take.
- 03
Enter the next car's price, its sales tax, title and fees, your cash down payment, and the rate and term of the new loan. Experian's Q2 2026 new-car average rate was 6.35%.
- 04
Leave the depreciation benchmark at iSeeCars' 41.8% over five years unless you have a reason to change it. It applies to both cars and is a retail resale figure.
- 05
Read the months you would stay underwater, then the rolled balance, loan-to-value and payment beside the same figures without the old debt, and the year-by-year table.
Formula
Negative equity = payoff − trade-in value. Rolled loan = next car's price + tax and fees − down payment + negative equity. Loan-to-value = rolled loan ÷ price. Payment = the amortizing payment on the rolled loan at the new rate and term. Car value after m months = price × (1 − 41.8%) raised to the power m ÷ 60, iSeeCars' five-year rate compounded evenly. Months underwater = the first month the loan balance is at or below that value. The waiting figure runs the same test on your current loan against your current car's trade-in value.
Example
You owe $26,884 at 8% with 36 months left on a car the dealer values at $20,000, and want a $42,000 car with $3,900 of tax and fees, $2,000 down, at 6.35% over 72 months. The $6,884 of negative equity makes the loan $50,784, a loan-to-value of 120.9%, and the payment $850 instead of $735. It adds $1,412 of interest, so rolling it forward costs $8,296 in all. You would be underwater for 2 years 6 months: at the end of year one you owe $43,601 on a car worth $37,691. Starting even, the same loan would be underwater for 1 year 1 month. Keep paying $842 a month on the current car instead and it surfaces in about 1 year 2 months.
Definitions
- Negative equity
- Owing more on a car than it is worth. Also called being upside down or underwater.
- Payoff amount
- What it takes to close the loan today, including interest accrued since the last payment. It is the figure a dealer pays your lender.
- Loan-to-value (LTV)
- The loan balance divided by the car's value. Above 100%, the loan is larger than the car is worth.
- Rolling over
- Adding the negative equity from one car's loan to the loan on the next car, so you keep paying for the old car inside the new payment.
- GAP coverage
- Insurance or a loan addendum that pays the difference between a car's actual cash value and the loan balance after a total loss or theft.
Good to know
How a car loan ends up underwater
Negative equity comes from two curves that fall at different speeds. A car's value falls fastest in its first years and then levels off. A loan balance falls slowly at first, because early payments are mostly interest, and faster toward the end. Wherever the balance sits above the value, the owner is underwater. Three things push a loan there. The first is a small down payment, which starts the balance close to or above the value. The second is financing the sales tax, title and fees, which are real costs but add nothing to what the car is worth. On this page's defaults a $42,000 car with $3,900 of tax and fees and $2,000 down starts with a $43,900 loan, a loan-to-value of 104.5%, before any old debt is added. The third is a long term, which slows the fall in the balance while the value keeps dropping. The page follows iSeeCars' measured five-year depreciation of 41.8%, compounded evenly, and on that curve the same loan stays underwater for 1 year 1 month even starting even. Buyers who paid peak prices are now meeting the other side of those curves. Edmunds reported that 29.6% of trade-ins toward new vehicles carried negative equity in Q2 2026, averaging $6,884, a record for a second quarter, on trade-ins averaging four years old. Its head of insights, Jessica Caldwell, said buyers who financed at 2022's peak prices are starting to come back to trade in and are bringing thousands of dollars in old debt with them. Negative equity is not a sign of a foolish purchase. It is the normal result of a long, thinly funded loan against a depreciating asset, and the question is what to do about it.
What rolling it forward actually costs
When you trade in a car worth less than you owe, the dealer pays off the old loan in full and adds the shortfall to the new one. Nothing is forgiven. The old debt moves into the new loan, where it pays the new loan's interest for the new loan's term. On this page's defaults, $26,884 owed on a car worth $20,000 leaves $6,884 of negative equity. Rolled into a $42,000 car with $3,900 of tax and fees and $2,000 down, it raises the loan from $43,900 to $50,784, a loan-to-value of 120.9% on day one. At 6.35% over 72 months the payment rises from $735 to $850, and the extra interest comes to $1,412, so the old debt costs $8,296 in all by the time it is gone. The larger cost is time. With the old debt rolled in, the page puts you underwater on the new car for 2 years 6 months, against 1 year 1 month starting even. At the end of the first year you would owe $43,601 on a car worth $37,691. Edmunds' Q2 2026 figures show the same pattern across the market: buyers with negative equity on their trade-in paid $944 a month on average against $777 for all new-vehicle loans, and were projected to pay $16,270 of interest against $9,811. Rolling over also tends to repeat. A buyer who trades in again while still underwater on the rolled loan carries a larger shortfall into the next deal, often on a longer term to keep the payment manageable, and each round makes the next one harder. Seeing the full cost, in dollars and in months underwater, is the first step in deciding whether the new car is worth it now.
The case for waiting, and how to shorten the wait
The alternative to rolling negative equity forward is to keep the current car until what you owe falls below what it is worth. Every payment reduces the balance, and a car that is already several years old loses value more slowly in dollars than a new one, so the gap closes from both sides. On this page's defaults, paying $842 a month on the current loan at 8%, with 36 months left, brings the balance below the car's value after about 1 year 2 months. Trade then, and the next loan starts at $43,900 with a $735 payment rather than $50,784 and $850. Waiting has costs of its own. You keep making the payments, which build equity rather than being lost, and you keep the risk of repairs on an older car, which can be large. If the car is unreliable or unsafe, waiting may not be realistic. Several steps can shorten the wait. Extra payments go straight to principal on a simple-interest loan and close the gap faster than anything else. Refinancing the current loan to a lower rate moves more of each payment to principal, and the auto loan refinance page prices that. Selling privately instead of trading in can shrink the gap immediately, because a private buyer usually pays more than a dealer offers, although you must cover any remaining shortfall in cash before the title can transfer. A cheaper next car, a larger down payment or a shorter term on the new loan all reduce how long the old debt follows you. The year-by-year table shows the balance with and without the old debt beside the car's value, which makes it easy to test each of these against the rolled deal.
Protecting yourself while you are underwater
The months marked as underwater on this page are not only an accounting position. They are a period of real financial exposure. If the car is totaled or stolen, the insurer pays its actual cash value, what the car was worth just before the loss, and not what you owe. The difference remains your debt, owed on a car you no longer have, and at the same moment you need another car. On the defaults, a total loss at the end of the first year would leave a gap of about $5,911 between the $43,601 owed and the $37,691 value, before any deductible. GAP coverage exists for this situation. It pays the difference between the actual cash value and the loan balance, and it is worth most when the loan-to-value is high and the term is long, which is exactly the profile of a rolled-over loan. The gap insurance page weighs its price against the risk. Two cautions about the figures themselves. The value curve follows iSeeCars' measured five-year depreciation of 41.8%, which is based on retail resale prices, and a trade-in offer normally comes in below retail. The real underwater window is therefore longer than this page shows, so treat the months as the optimistic end of the range. Depreciation also varies by vehicle: iSeeCars measured 34.2% for trucks and 57.2% for electric vehicles over the same five years, and the benchmark field can be changed to match. Lenders impose their own limits as well. Most restrict how far above the car's value they will lend, so a large amount of negative equity can require a bigger down payment or a cheaper car before a loan is approved at all. And stretching the term to hold the payment down is the one response that makes every other figure on the page worse.
Frequently asked questions
What is negative equity on a trade-in?
Owing more on your current car than the dealer will pay for it. On the defaults you owe $26,884 on a car worth $20,000 as a trade-in, so $6,884 of old loan is added to the next one. Edmunds found 29.6% of trade-ins toward new vehicles carried negative equity in Q2 2026, averaging $6,884.
What does rolling negative equity into a new loan cost?
More than the negative equity itself, because you pay interest on it for the whole new loan. On the defaults the $6,884 raises the loan from $43,900 to $50,784 and the payment from $735 to $850, adding $1,412 of interest over 72 months at 6.35%. The old debt costs $8,296 in all by the time it is paid off.
How long will I be upside down on the new car?
On the defaults, 2 years 6 months. Starting even, the same car and loan would be underwater for 1 year 1 month, because the tax and fees are financed too. The rolled-in debt more than doubles that window. These figures use iSeeCars' retail resale depreciation, and a trade-in comes in below retail, so the real window is longer.
What is loan-to-value?
The loan balance as a share of the car's value. On the defaults the rolled loan is 120.9% of the $42,000 price on day one, against 104.5% without the old debt. Anything above 100% means you owe more than the car is worth, and lenders limit how far above that they will lend.
Is it better to wait before trading in?
Often, if the current car is reliable. On the defaults, continuing to pay $842 a month on the current loan at 8% brings what you owe below what the car is worth after about 1 year 2 months. Trade then and the next loan starts at $43,900 with a $735 payment instead of $50,784 and $850. Waiting costs those months of payments and any repairs the older car needs.
Do I need GAP coverage if I roll over negative equity?
It is worth pricing. While you are underwater, a total loss or theft is settled at the car's actual cash value, not at what you owe, so the shortfall would be yours to pay on a car you no longer have. GAP coverage pays that difference, and it matters most in exactly the months this page marks as underwater.