Note: costs mentioned below are given in US dollars as a general point of reference — actual prices vary by country, currency, and local market.
Most used cars lose 15-20% of their value in year one and roughly 10-15% per year after that, so a $30,000 car is typically worth around $21,000-$25,000 after one year and $13,000-$16,000 after four years, before mileage and condition adjustments. Start from that curve, adjust for mileage against average, service history and accident record — then, crucially, check the result against live listings for the same specification in your own area, because local supply and demand can move the number by 5–10% in either direction and no published guide figure captures it.
At a glance
| Factor | Typical swing on value |
|---|---|
| Age (year 1 depreciation) | -15% to -20% |
| Mileage 20% above average | -5% to -10% |
| Full service history | +3% to +8% |
| One prior accident (repaired) | -10% to -20% |
| High local demand / low supply | +5% to +10% |
The three things any valuation needs
Any valuation worth acting on rests on three things: the car's age and trim (to find a baseline from recent comparable sales), the mileage (to adjust against the average for that age), and the condition/history (accidents, service records, number of owners). Skip any one of these and the number is closer to a guess than a valuation. Note also what none of this can be done without: current market data. A car's value is not a property of the car, it is what comparable cars are transacting for this month, which is why the cross-check against live listings below is not an optional last step but the actual answer.
Average mileage is commonly assumed at 12,000-15,000 miles (19,000-24,000 km) per year. A car with meaningfully less than that for its age is worth more; one with meaningfully more is worth less, often by 1-2% of value for every 1,000 miles above or below average, though this varies by segment — high-mileage tolerance is greater for trucks and diesels than for small hatchbacks.
How the depreciation curve works
New cars lose value fastest in the first 12 months — often 15-20% — because that's when the largest jump from 'new' to 'used' registration status happens. After that, depreciation slows to roughly 10-15% per year through years two to five, then flattens further as the car settles into the used-car market on its own merits rather than being compared to its new price.
| Car age | Typical % of original price remaining |
|---|---|
| 1 year | 78-85% |
| 3 years | 50-60% |
| 5 years | 35-45% |
| 8 years | 20-30% |
Adjustments that move the number the most
Accident and title history
A documented prior accident — even one that was properly repaired — typically knocks 10-20% off value versus an accident-free comparable, because buyers and dealers price in the uncertainty of hidden damage. A branded/salvage title is far more severe, often 35-50% off, and some lenders won't finance those cars at all.
Service history and ownership count
A complete, stamped service history (or digital equivalent) adds 3-8%, since it de-risks the purchase for the next owner. Each additional previous owner beyond one or two shaves off a smaller amount, typically 1-3% per owner, reflecting perceived inconsistency of care.
Local market conditions
The same car can be worth 5-10% more in a region where that model is in short supply or particularly popular (a 4x4 truck in a rural, snowy area; a small efficient hatchback in a dense city with congestion charging). National guide-book values are a starting point, not a local guarantee.
Where to get the real number
Once you have a ballpark, cross-check it against eight to ten live listings for the same year, trim and comparable mileage in your area, and against at least one recent sold or auction comparable if you can find one — asking prices run above what cars actually transact for, commonly by 5–10%.
The sources that give a genuine, current figure are:
- Major listings sites for your market, filtered to your model, year, trim, mileage and region. This is the closest thing to live market data available free, and it is more reliable than any single guide figure.
- Published valuation guides — Kelley Blue Book, Edmunds and NADA in the US; Parkers, Auto Trader and Glass's or CAP in the UK. Each publishes separate trade-in, private-sale and retail figures, and the gap between them is the point, not an error.
- Instant online buying services and dealer trade-in offers. Getting two or three costs nothing and produces a firm, real number — the floor beneath which you should not sell.
- Recent auction results where you can see them, which reflect trade values rather than asking prices.
Do not treat one figure from one source as the value. Gather three or four and you will have a range, which is what a used car actually has.
Trade-in offers from dealers are typically 10-20% below private-sale value, because the dealer needs margin to resell and cover reconditioning. That gap is normal, not a sign you're being lowballed — it's the cost of convenience and speed.
Frequently asked questions
How accurate are online used car value estimators?
Does color affect a used car's value?
Is private sale or trade-in worth more?
How much does high mileage reduce value?
Should I get an independent inspection before trusting a value estimate?
Sources & further reading
- Kelley Blue Book – How Car Depreciation Works
- Edmunds – True Cost to Own & Depreciation Data
- Consumer Reports – Used Car Buying Guide
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
