How the estimate is built
The three comparable prices are averaged, so one unusual asking price cannot dominate. The mileage adjustment is the difference between the comparables' average mileage and yours, divided by 1,000 and multiplied by the rate you enter.
If your car has lower mileage, the adjustment is positive. The estimate is the average plus that adjustment, and it never falls below zero.
Worked example
Comparables at $15,500, $16,200 and $15,100 average $15,600. Their average mileage is higher than the subject car's, so 15,000 miles at $120 per 1,000 adds $1,680. The adjusted estimate is $17,280.
These prices are illustrative. Use real comparables for the same model, year, gearbox and rough condition.
Choosing comparables
Use cars of the same generation, engine and trim, sold or advertised in the same region and within a few months. An asking price is not a sale price, so treat dealer retail and private sale figures as different populations.
Three comparables is the minimum for a stable average. If the spread between them is large, the estimate is weak regardless of the arithmetic, and the spread figure shows that.
Limits of this calculator
It does not adjust for condition, service history, options, colour or accident history, and it assumes a straight-line mileage relationship. It is not a trade-in offer or an insurance valuation.
For the value lost over time, use the car depreciation calculator.
For the value lost over time, use the US car depreciation calculator.
Inputs for the US car value calculator
First comparable price
Asking or sold price of the closest comparable you have found.
Second comparable price
A second car of the same model, year and rough condition.
Third comparable price
A third comparable, so one unusual price cannot dominate the average.
Average mileage of the comparables
The mean mileage across the three cars you entered.
Mileage of your vehicle
The odometer reading of the car being valued.
Value per 1,000 miles
What each 1,000 miles is worth in your market. Enter 0 to ignore mileage.
CALCULATOR QUESTIONS
Car value calculator US questions
Should I use asking prices or sold prices?
Sold prices are better. Asking prices are usually higher and need a discount to compare with a real transaction.
What mileage rate should I use?
There is no universal figure. It varies by model and market, so test a couple of values to see how much the estimate moves.
Why only three comparables?
Three is enough to stop one outlier dominating while keeping the page quick to use. More comparables would improve it.
Is this a part-exchange offer?
No. A dealer offer will be lower, because it reflects trade margin and reconditioning cost.