Methodology

The state averages

Source

The cost figures on the home-page receipt, the cost map and every state page come from the National Association of Insurance Commissioners (NAIC), Auto Insurance Database Report 2022/2023, released February 13, 2026. Its 2023 state tables are the latest year the NAIC has published by state. We copy the published figures and round them to whole dollars.

What each figure means

All figures are per insured vehicle, per year.

• Average expenditure: the total premium drivers paid for liability, collision and comprehensive coverage, divided by the number of insured vehicles for the year. It mixes cars with liability only and cars with full coverage. In 2023 the U.S. figure was $1,282.
• Liability, collision, comprehensive: the average premium for each coverage, among vehicles that carried it.
• Combined premium (full coverage): what a vehicle carrying all three coverages paid on average. In 2023 the U.S. figure was $1,438.
• Change from 2022: the state’s 2023 average expenditure compared with its 2022 figure, as a percentage.
• Compared with the U.S.: the state’s 2023 average expenditure divided by the U.S. average, minus one, as a percentage.

Map tiers

The cost map colors each state by its 2023 average expenditure: under $1,000; $1,000 to $1,249; $1,250 to $1,499; and $1,500 or more.

What the averages can’t tell you

These are averages of what drivers paid in 2023, not quotes. Your own price depends on your record, car, ZIP code, coverage and insurer. When you enter a ZIP code on the site, it finds the state from the ZIP’s first three digits and shows that state’s average. There is no ZIP-level figure.

Other data sources

• Uninsured drivers: the Insurance Research Council’s estimates for 2023, the share of drivers in each state with no insurance.
• Price trends: the Bureau of Labor Statistics Consumer Price Index for motor vehicle insurance.
• Rules and programs: state insurance departments, state statutes and regulations.

How state pages are researched

Each state page starts from the NAIC figures above. The rules are then researched on official sources: the state insurance department, the motor vehicle agency and the statutes. Each page covers the minimum liability limits and other required coverages, how the state reviews insurers’ rates where its regulator says so, whether insurers may use credit-based insurance scores, what drivers turned down by insurers can do, and how to file a complaint. Every state page lists its sources and the date they were checked. The editorial policy explains how pages are kept current.

The calculators

All three calculators run in your browser on the numbers you enter. They show examples, not offers.

Deductible break-even calculator

The deductible break-even calculator asks whether a higher deductible pays for itself.

• Yearly saving = current premium − premium with the higher deductible
• Extra cost per claim = higher deductible − current deductible
• Break-even years = extra cost per claim ÷ yearly saving

The result is the number of claim-free years it takes for the premium saving to cover one claim’s extra cost. It assumes the claim is larger than the higher deductible. When the damage is smaller than that, the higher deductible costs you less extra on that claim than the calculator shows.

Monthly vs. pay-in-full calculator

The monthly vs. pay-in-full calculator shows what a monthly plan costs over paying the term at once.

• Extra cost = down payment + number of installments × (installment + installment fee) − pay-in-full price
• APR = 12 × the monthly rate at which the installments, paid one month apart starting a month after the down payment, are worth exactly the pay-in-full price minus the down payment today

The monthly rate has no closed formula, so the calculator finds it numerically. When the plan costs nothing extra, the APR shown is 0. An insurer’s installment plan is not a loan. The APR is there only so you can compare the plan’s cost with a credit card or a loan.

Pay-per-mile calculator

The pay-per-mile calculator compares a per-mile policy with your current premium.

• Monthly cost of the per-mile policy = base rate + miles driven × (cents per mile ÷ 100)
• Break-even miles = (current monthly premium − base rate) ÷ (cents per mile ÷ 100)

Below the break-even mileage, the per-mile policy costs less each month; above it, more. Many per-mile programs stop charging after a set number of miles a day. The calculator ignores that cap, so it overstates the cost of months with long trips.

Questions or errors

If a figure or formula looks wrong, tell us through the contact form or at [email protected].