Methodology & data sources

Transparency is the core of our E-E-A-T: this page documents where our data comes from, the vintage of each series, and the exact formula behind every derived number. FloodRate covers all 51 US states and DC and 11 FEMA flood zones. This snapshot was last compiled in June 2026.

The figures we publish

• Average annual NFIP premium (2026). The average National Flood Insurance Program premium per state, from FEMA's "Policy Information by State" report (the national average is about $976/yr). This is a statewide average across all in-force policies, not a quote for any particular property. US public domain.
• NFIP claims (since 1978). The cumulative number of NFIP claims per state, queried directly from the OpenFEMA FIMA NFIP Redacted Claims v2 dataset, which holds claim records back to the program's start. These are counts of claims, not dollar amounts. US public domain.
• Dominant flood zones & coastal flag. The FEMA flood-zone codes that dominate a state's mapped floodplains and whether it has ocean, Gulf or Great-Lakes coastline — used for context and risk framing, not pricing.
• Flood-zone definitions. Verbatim FEMA definitions of each zone (A, AE, AH, AO, AR, A99, V, VE, X shaded/unshaded, D), whether it is a Special Flood Hazard Area, and where insurance is mandatory. From FEMA's Flood Zones glossary. US public domain.

All figures are captured as a committed static snapshot. We do not invent numbers; the only values we generate ourselves are the clearly-labelled estimates below.

The premium estimator formula

Our flood-insurance estimator gives a rough annual premium by scaling a state's average premium by your coverage and a flood-zone risk factor:

estimate = state baseline premium × (coverage ÷ $250,000) × zone risk factor

The state baseline is the FEMA NFIP average premium; coverage scales linearly off the $250,000 NFIP building-coverage maximum; and the zone risk factor (below) reflects relative premium levels across zones. A practical minimum of about $120 is applied. The factors are illustrative — they are our own relative weights for an educational estimate, not FEMA rates.

The Risk Rating 2.0 caveat (important)

Since October 2021, fully phased in by April 2023, FEMA prices NFIP policies with Risk Rating 2.0. Premiums are now set per individual property using factors such as distance to water, flood type and frequency, foundation type, the height of the lowest floor relative to the base flood elevation, prior claims and the structure's replacement cost. Because of this, no published formula can reproduce a real quote, and two homes on the same street can pay very different premiums. Our state averages and estimator are benchmarks for general understanding only — they are not Risk Rating 2.0 prices.

Important limitations

• Statewide averages. A state average hides huge property-level variation; a coastal or riverside home can cost far more than its state average.
• Cumulative claims. Claim counts run since 1978 and partly reflect how many policies a state has, so large states naturally rank high.
• Different vintages. Premiums (2026) and claims (cumulative) come from different windows.
• Not a quote. The estimator ignores all property-specific Risk Rating 2.0 inputs.

Treat every figure as an estimate for general information — verify with FEMA, FloodSmart.gov or a licensed agent before making a decision. This is not insurance or financial advice. See our disclaimer.

Data sources

How calculations work

The estimator runs entirely in your browser using the published formula above. We do not store your inputs.