How it works
A gap-insurance decision rests on one ratio and one timeline: how far underwater the loan sits today, and how many months pass before amortization outruns depreciation. Loan-to-value above roughly eighty percent opens the discussion because a total loss tomorrow would strand the difference between the insurer's market-value payout and the payoff quote — money owed on a car you no longer own. The calculator projects both curves monthly: the balance compounding at your APR while payments retire it, the value eroding at the depreciation input's pace, marking the month equity turns positive and tracking the deepest negative point along the way. Expected benefit then prices the risk rationally — total-loss frequency for financed vehicles runs near two percent a year, so average negative equity across the exposed window, weighted by those odds and their duration, gives the statistical value of the guarantee. Against it stand two price regimes: dealership gap sold once for hundreds (and often rolled into the loan, where interest compounds it further) versus carrier riders costing tens annually and cancellable the moment equity turns positive. Small down payments, long terms and high APRs stretch the underwater window dramatically; twenty-percent-down buyers rarely need the product at all, which is why the recommendation keys off measured equity rather than habit.
Formula
LTV = balance / value | each month: balance += balance x APR/12 - payment; value x= (1 - dep%)^(1/12)
Tips
- Buy gap from your insurer as a rider after closing day — dealer F&I pricing runs several multiples higher.
- Never roll gap into the loan if avoidable; interest turns a $695 product into an $800 one.
- Cancel the rider the month equity flips positive — the schedule here marks it precisely.
- Leases include gap automatically; decline the dealer's duplicate offering without guilt.
- Refinancing out of negative equity rarely works — lenders cap LTV, so curing the gap means paying principal down.
Frequently asked questions
- Is gap insurance worth it?
- Worth it whenever loan-to-value sits high enough that a total loss strands real money: on these inputs LTV is about 124%, negative equity $4,800, and the odds-weighted payout across the underwater window runs a few hundred dollars — easily justified via a cheap insurer rider, marginal at dealer pricing.
- How much does gap insurance cost?
- Dealerships charge $400-$900 one-time, frequently financed with interest; auto-insurer riders typically cost $20-$60 a year and cancel anytime. Identical protection at wildly different prices is exactly why declining F&I office offers pays.
- How do I know if I have negative equity on my car?
- Compare your lender's payoff quote against private-party resale value, not trade-in figures. This calculator projects the path directly: starting $4,800 underwater at defaults, you cross into positive equity around month 22 as payments outrun 17%-a-year depreciation.
- When can I cancel gap coverage?
- As soon as the loan balance falls below the car's value — the equity-positive month this tool identifies. Rider policies refund pro-rata without fuss; financed dealership gap requires chasing a third-party administrator, another quiet argument for riders.
- Does gap insurance cover missed payments or rollovers?
- No — gap covers only the shortfall between market-value settlement and payoff after a covered total loss, sometimes plus your deductible. Missed payments, mechanical breakdowns and negative equity rolled in from a previous trade remain entirely your problem.