Extended Car Warranty Calculator
The contract, the car's factory coverage, and the repairs you expect
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 warranty costs in total and its deductible per repair visit. If you were quoted a monthly price, multiply it by the months you would pay.
- 02
Enter the term in years and miles as the contract states them, counted from today, and the miles you drive a year. Coverage ends at whichever limit comes first.
- 03
Enter how much of the factory bumper-to-bumper warranty the car has left, in years and miles. Any overlap is time the contract charges for but the factory already covers.
- 04
Enter your own estimate of the chance of a covered repair in a year once the factory warranty ends, and the average bill for one. The break-even stats show how pessimistic those guesses would have to be.
- 05
Read the expected payout against the price, then the schedule, which shows which coverage runs each year and what the same money would look like in a savings account.
Formula
Term that runs = the lesser of the contract's years and its mileage limit ÷ your miles a year. Factory coverage left = the lesser of its years left and its miles left ÷ your miles a year. Years the contract adds = term that runs − factory coverage left, never below zero. Expected covered repairs = years added × your yearly chance of a covered repair. Expected payout = expected covered repairs × (average bill − deductible). Expected value = expected payout − price. Break-even yearly chance = price ÷ (years added × (average bill − deductible)). Break-even bill = price ÷ (years added × yearly chance) + deductible. The self-insured fund starts at the price, earns your savings yield and pays the full expected bills in each year of added coverage.
Example
A $3,000 contract with a $100 deductible runs 5 years or 60,000 miles from today on a car driven 13,500 miles a year, so it actually ends after 4.4 years. The factory bumper-to-bumper warranty has 1 year or 10,000 miles left, which runs out after 0.7 years, so the contract adds 3.7 years of coverage and about $500 of its price overlaps the factory's. At a 20% yearly chance of a covered repair averaging $1,200, you can expect 0.74 covered repairs worth $1,100 each after the deductible: an expected payout of $815, or $0.27 per dollar, and an expected loss of $2,185. It would break even only at a 74% yearly chance of a repair, an average covered bill of $4,150, or three covered repairs. Kept in savings at 3.5% instead, the $3,000 pays the $889 of expected bills in full and leaves about $2,562 when the term would have ended; building it month by month would take $56 a month.
Definitions
- Extended warranty
- The common name for a vehicle service contract: a separately priced agreement to pay for listed repairs for a set number of years or miles, beyond or alongside the manufacturer's warranty.
- Factory warranty
- The manufacturer's own coverage included in a new car's price, usually split into a shorter bumper-to-bumper term and a longer powertrain term.
- Deductible per visit
- What you pay toward each covered repair visit before the contract pays the rest.
- Expected value
- The average outcome if the same bet were made many times: here, the expected payout less the price. A negative figure means the contract is expected to cost more than it returns.
- Self-insuring
- Keeping the money a warranty would cost and paying repairs from it yourself. You keep the seller's margin and carry the risk of an early, large repair.
Good to know
What an extended warranty really is, and who it pays
What is sold as an extended car warranty is usually a vehicle service contract: a separately priced agreement, sold by a dealer, a manufacturer or a third-party company, to pay for listed repairs for a set number of years or miles. Unlike the factory warranty, which is built into a new car's price, you pay for it directly, and its price has to cover the repairs the seller expects to pay plus administration, sales commissions and profit. That is why, on average, buyers get back less than they pay. It is the same logic as any insurance: the seller pools many customers, most of whom claim little, and prices the contract above the average claim. The contract can still be the right purchase for some buyers. Insurance is worth buying when a loss would be hard to absorb, not when it is merely unwelcome. A driver with no savings who depends on the car for work may reasonably pay a premium to turn an unpredictable $3,000 repair into a known cost. A driver who could pay that bill from savings is usually better off keeping the seller's margin. This page puts numbers on that trade. It estimates how many covered repairs you can expect in the years the contract adds beyond the factory warranty, values each one at the average bill less the deductible, and compares that expected payout with the price. On the example, a $3,000 contract returns an expected $815, about 27 cents per dollar, an expected loss of $2,185. The break-even figures turn the question around: how likely a covered repair would have to be, 74% a year in the example, or how large the average bill, $4,150, for the contract to pay for itself. If those break-even figures look implausible for your car, the contract is priced for someone else's risk.
The survey evidence: most contracts are never used
Independent evidence on how extended warranties work out for buyers is scarce, and the most detailed study is more than a decade old. In late 2013 the Consumer Reports National Research Center surveyed more than 12,000 subscribers who had bought an extended warranty on a 2006 to 2010 model-year car. Fifty-five percent had not used the contract for any repair during its life. The median buyer paid $1,214, and among those who did use it the median amount of repairs covered was $837, so even the typical buyer who made a claim came out behind. Fewer than 30% said they would definitely buy one again, and satisfaction ranked among the lowest of all the products and services Consumer Reports surveyed. The findings varied with reliability. Owners of less reliable brands used their contracts more often, including 71% of BMW owners and 63% of Dodge owners, while only 39% of Honda and Toyota owners and 36% of Subaru owners did. That pattern is the useful part for a buyer today: a contract's value depends heavily on how likely your particular model is to need expensive repairs. Prices have moved since the survey. Cars.com collected quotes from 11 extended warranty companies in February 2026 and found an average of $139 a month, with powertrain-only contracts averaging $117, stated-component contracts $139 and bumper-to-bumper contracts $160. Consumer Reports also found that about a third of buyers negotiated the price, saving an average of $325, so the first quote is rarely the last. On this page the three survey figures sit in advanced fields so the survey's own arithmetic stays visible: a 45% chance of using the contract at a median $837 of covered repairs is about $377 of expected value against $1,214 paid. Use your own estimates for the main calculation, and the survey as a check on how optimistic they are.
Timing, overlap and the fine print that decides value
Two contracts with the same price can be worth very different amounts, because what you are really buying is the coverage that runs after the factory warranty ends. Most mainstream brands cover a new car for 3 years or 36,000 miles bumper-to-bumper and 5 years or 60,000 miles on the powertrain, and some brands offer longer terms. A service contract bought with a car and counted from the day of sale overlaps whatever factory coverage remains, so part of its price pays for repairs the manufacturer would have covered anyway. On the example, a 5-year contract bought with 1 year or 10,000 miles of factory coverage left spends its first 0.7 years overlapping, about $500 of the $3,000 price. Consumer Reports advises avoiding that overlap, and many contracts can be bought later, closer to the end of the factory warranty. Mileage limits matter just as much. Coverage ends at whichever limit arrives first, so a 60,000-mile limit on a car driven 13,500 miles a year ends after about 4.4 years, not the 5 printed on the contract. Before signing, read what is actually covered. Bumper-to-bumper or exclusionary contracts list what they do not cover; stated-component contracts cover only the parts they name, which can leave gaps. Check how the deductible applies, whether you must use particular repair shops, whether wear items are excluded, how claims are approved, and whether the contract can be transferred or cancelled for a refund if you sell the car. Consumer Reports also suggests checking whether a bumper-to-bumper plan includes towing and rental reimbursement, and reviewing any shop network restrictions. A cheap contract that denies claims or limits where you can get repairs is worth less than its price suggests, whatever the expected-value arithmetic says.
Self-insuring: when a repair fund beats a contract, and when it does not
The alternative to buying a contract is keeping the money and paying repairs yourself, which is what Consumer Reports recommends: put what the warranty would cost in an interest-bearing account and draw on it for repairs after the factory warranty ends. On the example, $3,000 deposited today at a 3.5% yield pays the $889 of expected repair bills in full, with no deductible, and leaves about $2,562 when the contract would have ended. That leftover is the seller's margin, returned to you. Self-insuring has one real weakness: timing. Expected value describes the average outcome, and any single car can have a bad year. If a $4,000 repair arrives in the first months, a $3,000 fund cannot cover it, while the contract would have. Three habits reduce that risk. First, build the fund before the factory warranty ends, so it is full when the risk begins; building the example's $3,000 from zero over the contract's 4.4 years takes about $56 a month. Second, keep it separate from your general emergency fund, or size that fund with a large repair in mind, so one repair does not leave you exposed to a job loss or medical bill at the same time. Third, keep the car on its maintenance schedule, since neglected small problems are a common route to large bills. Self-insuring is the better choice for most drivers who could pay a four-figure repair without borrowing, and it looks better still with a reliable model and low annual mileage. A contract is easier to justify for a model with a poor reliability record, for a driver who plans to keep a car well past its factory warranty with no savings to fall back on, or for a vehicle whose known weak points are expensive to fix. Even then, negotiate the price and avoid paying for overlap.
Frequently asked questions
Is an extended car warranty worth it?
On average it is not, because the price has to cover the seller's costs and profit as well as the repairs. On this page's example, a $3,000 contract with a $100 deductible, a 20% yearly chance of a covered repair and a $1,200 average bill is expected to pay out $815, about 27 cents per dollar, an expected loss of $2,185. It can still suit a buyer who could not absorb a large repair bill, or a model known for expensive failures.
What did Consumer Reports find about extended warranties?
Its survey of more than 12,000 subscribers who bought one on a 2006 to 2010 model-year car, taken in late 2013, found that 55% had never used it. The median buyer paid $1,214, and those who did use it had a median $837 of repairs covered. Fewer than 30% said they would definitely buy one again. The survey is old, and prices have risen since, but it remains the most detailed independent evidence on how these contracts work out.
How much does an extended car warranty cost in 2026?
Cars.com collected quotes from 11 providers in February 2026 and found an average of $139 a month, ranging from $30 to $250. Powertrain-only cover averaged $117 a month, stated-component plans $139 and bumper-to-bumper plans $160. The price depends on the car's age, mileage and make, the coverage level and the deductible, and Consumer Reports found that buyers who negotiated saved an average of $325.
Why does overlap with the factory warranty matter?
Because you pay for months in which the factory already covers the same repairs. In the example the contract actually runs 4.4 years, the first 0.7 of which sit inside the factory warranty, so about $500 of the $3,000 price buys protection the car already has. Consumer Reports advises avoiding that overlap.
What is the break-even chance of a repair?
The yearly chance of a covered repair at which the expected payout equals the price. In the example it is 74%, against the 20% entered, so you would need to expect a covered repair in nearly three years out of four for the contract to pay. The page also shows the break-even average bill, $4,150 in the example, and the number of covered repairs it takes to recover the price, three.
What is the alternative to buying an extended warranty?
Setting the money aside yourself. Consumer Reports suggests putting what the warranty would cost into an interest-bearing account instead. In the example, $3,000 deposited at 3.5% pays the $889 of expected repair bills in full, with no deductible, and leaves about $2,562 when the contract would have ended. The risk you keep is a large repair early on, before the fund has grown, which is where an emergency fund comes in.
Does the mileage limit change the value?
Yes, often more than the years do. Coverage ends at whichever limit arrives first. At 13,500 miles a year a 60,000-mile limit ends the example contract after 4.4 years, not the 5 years on its face, so a high-mileage driver can pay for years of coverage they never reach.