How We Calculate

At a glance:
  • Base data: NAIC combined average premium by state (2023)
  • Adjustments: age, driving history, coverage level
  • Inflation: CPI-U motor vehicle insurance (BLS)
  • Purpose: educational estimates, not quotes
  • Limits: insurer, ZIP, vehicle, and personal factors not modeled

Overview

Our estimates use publicly reported state-level combined average premium (written premium / exposures) from the National Association of Insurance Commissioners (NAIC). We apply generalized adjustment factors for age, driving history, and coverage level. These are illustrative ranges only, not binding offers. Individual rates depend on your specific profile, vehicle, ZIP code, and insurer.

Base Year (2023 NAIC)

Our base dataset is the NAIC 2022/2023 Auto Insurance Database Report, Table 5 (2023 Combined Average Premium by state). We do not claim NAIC data for years after 2023. The base year remains 2023.

Inflation Adjustment

When displaying estimates for a target year after the base year, we apply a compounded inflation adjustment using December-to-December annual percentage changes from the Bureau of Labor Statistics CPI-U Motor Vehicle Insurance series. The adjustment is illustrative and reflects broad industry trends. It is not insurer-specific pricing and does not account for regional or individual variation.

Inflation Adjustment Source

Bureau of Labor Statistics, CPI-U Motor Vehicle Insurance

Series ID: CUUR0000SETE

Annual percent change based on December-to-December CPI-U Motor Vehicle Insurance index.

https://data.bls.gov/timeseries/CUUR0000SETE?output_view=data

Formula

Estimated annual = (State base premium × inflation factor) × Age multiplier × Risk multiplier × Coverage multiplier

We apply a range (typically 90% to 110%) to reflect variation. Base premiums come from NAIC-reported state-level combined average premium (2023). Multipliers are generalized adjustment factors based on typical industry patterns for age brackets, driving history, and coverage levels.

Disclaimer

  • These estimates are illustrative only, not insurer offers, binding prices, or representations of what any insurer will charge.
  • Actual premiums vary by insurer, location, vehicle, and personal factors.
  • Always obtain pricing directly from licensed insurers.

Limitations

  • Individual rates depend on insurer, ZIP code, vehicle, credit-based score, and other factors we do not model.
  • The inflation adjustment is a broad approximation and does not represent any specific insurer's rate changes.

Frequently asked questions

Where does the base data come from?

State-level combined average premiums come from the NAIC. See our sources page for the exact report and table.

How often is data updated?

We use the latest NAIC report available (currently 2023). When new reports are published we may update the base year and note it on the sources page.

What are the limitations?

We don't model your ZIP, vehicle, insurer, or credit. The result is a ballpark. Always get quotes from insurers for your real rate.

How do the multipliers work?

Age, driving history, and coverage level each have a factor (e.g. young drivers higher, clean record lower). We combine them with the state base to get a range.

Is the inflation adjustment exact?

No. We use CPI-U motor vehicle insurance for a broad trend. Your insurer's rate changes can differ.