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. A value estimator starts from that depreciation curve, then adjusts up or down 5-15% for mileage versus average, service history, accident record and local supply and demand.
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 numbers every estimator needs
A useful used car value estimator needs three inputs at minimum: 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 you get is closer to a guess than an estimate.
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 check your estimate against real listings
Once you have a ballpark number, cross-check it against 8-10 live listings for the same year/trim/mileage in your area, and against at least one recent 'sold' or auction comparable if you can find one — asking prices run higher than what cars actually transact for, often by 5-10%.
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.
