Editorial policy

Here’s where the estimator gets its numbers and how we make sure they’re right.

Information sources we rely on

For the age curve, we use Kelley Blue Book's table of average new-car depreciation.
Our type and model rates come from iSeeCars' 2026 research, which covered over 950,000 five-year-old cars.
With NHTSA's free vPIC service, you can decode a VIN and view a list of vehicle makes and models.
For the market adjustment, we draw on the price index covering used cars and trucks from the Bureau of Labor Statistics.

When no public source provides a figure the model requires, we label it our assumption. Examples are 12,000 miles a year and 3% per 10,000 miles.

Checking our numbers

Before every build, we run two worked examples against the model and stop the build if either result differs. Whenever the site is rebuilt, we refresh the price index from the BLS series and print its month under every result. Once each year, the type and model rates change as iSeeCars publishes a new study.

For any errors you find, email contact@whatismycarworth.net. After checking the reported error against its source, we correct the model and the page.

Independence

None of the carmakers, dealers, lenders or valuation companies pays for this site or sees the figures before you do. Because the site has no ads, affiliate links or lead forms, the figure you get doesn't affect anything here.