Methodology
Exactly how we produce every number on this site — the data we start from, the factors we model, and the limits you should know about.
1. The base figure: real state averages
The headline cost on each state page is not estimated. It is the combined average premium per insured vehicle for that state, taken directly from the NAIC 2022/2023 Auto Insurance Database Report — the official dataset compiled by the National Association of Insurance Commissioners (2023 data, released February 2026). "Combined" means it reflects liability, collision and comprehensive coverage together.
The national benchmark we compare each state against ($1,438/year) is the NAIC countrywide combined average from the same report.
2. The calculator: published rating factors
The calculator starts from your state's real NAIC average and adjusts it using published industry multipliers for the variables that insurers are known to weigh. These multipliers are drawn from secondary public sources such as Bankrate and ValuePenguin modeled rates:
| Factor | What it reflects |
|---|---|
| Driver age | Younger and very senior drivers typically pay more |
| Driving record | At-fault accidents and DUI/DWI raise rates |
| Credit tier | Credit-based insurance score, where legally permitted |
| Coverage level | Full coverage vs. state-minimum liability |
These factors are applied as approximate ratios to the state base. They are directional estimates, not an insurer's actual rating algorithm.
3. Where we follow state law
We respect state rating rules. For example, in the four states that ban credit-based insurance scoring — California, Hawaii, Massachusetts and Michigan — the calculator does not apply any credit adjustment, because insurers there legally cannot. State rules are sourced from state statutes and insurance regulators.
4. What we do not do
- We do not collect your personal data to produce an estimate — the calculator runs entirely in your browser.
- We do not sell insurance and are not an agent or broker.
- We do not present estimates as binding quotes. Only a licensed insurer can give you a real rate.
- We do not adjust our published averages based on advertising or affiliate relationships.
5. Updates & corrections
We refresh state averages when the NAIC releases a new annual report. If you spot an error or have a data source to suggest, email [email protected] — we correct verified issues promptly.