Earthquake Insurance Cost Calculator

Earthquake coverage is excluded from standard homeowners — you need a separate policy (CEA in California, private in other states). Premium scales with USGS seismic zone, building type, and the deductible percentage you choose.

Seismic Zones and Premium

USGS hazard maps drive rate-setting. California (San Andreas, Hayward, San Jacinto faults) has the highest premiums. Pacific Northwest (Cascadia Subduction Zone) is rising as awareness grows. New Madrid Seismic Zone covers MO/TN/AR/KY/IL.

Building Type Matters Most

Wood-frame homes flex and survive better than rigid structures. Unreinforced masonry (URM), soft-story apartments over open garages, and old brick chimneys raise premium 60-100%. Reinforced concrete with shear walls gets discounts up to 30%.

Deductibles 5%-25%

Earthquake deductibles are percentage-of-dwelling, not flat dollar. Common: 10%, 15%, 20%, 25%. On a $500K house, 15% deductible = $75K out-of-pocket before insurance pays. Higher deductible cuts premium 15-30%.

Retrofit Discounts

Brace-and-bolt foundation retrofits, soft-story strengthening, and seismic gas shutoff valves earn 5-25% premium discounts. California offers Brace+Bolt grants (up to $3K) and Earthquake Brace+Bolt program in select zip codes.

How This Calculator Prices Earthquake Coverage

Earthquake insurers quote a rate per $1,000 of insured value rather than a flat annual price, and this tool follows the same structure so you can audit the number. It starts from a base rate of $3.50 per $1,000 of dwelling limit plus 40% of your contents limit, then multiplies by a seismic-zone factor, a building-type factor and a deductible factor. The table below holds everything constant — a $500,000 wood-frame dwelling, $100,000 of contents, a 15% deductible — and varies only the zone, so you can see how much of the premium is pure geography.

Building type moves the same premium a long way again: unreinforced masonry doubles it, a soft-storey building over an open garage adds 60%, and reinforced concrete with shear walls cuts it by 30%. Zone assignments follow USGS National Seismic Hazard Model hazard mapping.

Is Earthquake Insurance Worth It? The Break-Even Maths

The percentage deductible is what makes this decision unusual. On a $500,000 home a 15% deductible means $75,000 out of pocket before the policy pays anything, so an earthquake policy is not there for cracked drywall and a toppled bookcase — it is there for the rebuild. Run the comparison that way: in a California high-hazard zone you would pay roughly $4,725 a year, so about sixteen years of premiums equal the deductible you would still owe. That looks like a bad trade until you weigh it against the tail: the USGS UCERF3 forecast gives the San Francisco Bay Area a 72% probability of a magnitude 6.7 or greater earthquake within 30 years, and a total loss on an uninsured home is the whole $500,000 plus the mortgage that survives the building. The honest rule is that earthquake cover is worth buying when losing the house would be financially unrecoverable, and worth skipping when you could rebuild from savings. Raising the deductible from 15% to 25% cuts the premium 28% in this calculator, which is usually a better move than dropping cover entirely.

Updated 2026-08-31. Sources: CEA — California Earthquake Authority, USGS Earthquake Hazards.