Sources we use
We rely on primary sources: state DMVs, revenue departments, insurance departments and statutes; the National Association of Insurance Commissioners; the U.S. Energy Information Administration; the Bureau of Labor Statistics; the Federal Reserve; the IRS; the EPA and fueleconomy.gov; and AAA's Your Driving Costs study as a named benchmark. We do not use insurer advertising, dealer sites, forums or comparison sites as sources of fact.
How calculators are checked
Every calculator uses published, standard formulas. The code is covered by automated tests that check known answers (for example, a $30,000 loan at 7% for 60 months has a monthly payment of $594.04, and a 300-mile trip at 30 mpg uses 10 gallons of gas). We show the formula next to each tool so anyone can verify the result by hand.
What we will not publish
- Insurance quotes, quote forms or lead forms, and recommendations to buy from a particular insurer, dealer or lender.
- Paid placements, affiliate links or reviews written for an insurer, dealer or lender.
- Claims we cannot support with a source.
Updates and corrections
Each page shows the date it was last updated. When fee schedules, tax rates, minimum insurance limits, the NAIC averages, EIA fuel prices or AAA's yearly study change, we update the affected pages and their dates. If you find an error, tell us through the contact page and we will review it and correct it.