Methodology

Our goal is to give you a clear, defensible estimate you can sanity‑check against real quotes. Below we spell out the inputs we use, the math we apply, what the numbers mean, and how you can verify or replace them.

What goes into the estimate

• National baseline: A single annual premium starting point (USD) that reflects the typical cost of homeowners coverage across the U.S. In code, this is the NATIONAL_BASELINE constant. It can be updated as new market data becomes available.
• State multiplier: A factor for each state capturing relative pricing (e.g., coastal wind or wildfire exposure). These load from /data/state-multipliers.json when present, or fall back to placeholders. You can supply your own vetted file to improve accuracy.
• Your inputs (risk factors): dwelling coverage tier, deductible, roof age/material, claims in the last 5 years, and location risk (inland / standard / high wind‑hail / wildfire‑prone).

How the calculation works

We multiply a baseline by a state factor and by the product of your selected risk factors. This keeps the math simple, transparent, and easy to audit.

Estimated Annual Premium = Baseline × State × Coverage × Deductible × Roof × Claims × Location
    

Example (illustrative)

Suppose the current baseline is $1,800, your state factor is 1.10, and you select $250k dwelling (factor 1.00), $1,000 deductible (1.00), 6–15 year roof (1.00), no claims (1.00), and standard location (1.00). The estimate would be:

$1,800 × 1.10 × 1.00 × 1.00 × 1.00 × 1.00 × 1.00 = $1,980 (annual) ≈ $165/month
    

Values shown are examples; your selections and state factor determine the output you see on the page.

Data provenance & transparency

• State factors: Ship with placeholders (1.00) so the tool works everywhere. For better fidelity, replace them with a vetted source (e.g., summarized NAIC HO‑3 indices) by providing /data/state-multipliers.json.
• Versioning: The multipliers file can include meta.updated and meta.source. When present, the estimator displays a green “Data loaded” badge with the date so you know exactly what’s in use.
• Local control: If you upload a JSON in the browser, we store it locally (not on our servers) and use those values until you clear them.

Quality checks we run

• Inputs are validated before calculation; the UI guards against missing elements and binds events once.
• The breakdown panel shows every factor used in the final number so you can verify the math in seconds.
• State‑page URLs auto‑select the correct state and share links preserve the exact scenario via the query string.

Limits you should know about

• This is not an insurance quote or an offer of coverage. Actual pricing depends on underwriting, rating territories, construction, protection class, discounts/credits, and carrier rules.
• Catastrophe exposures and market conditions change; keep state factors current for best results.
• Some carriers apply special deductibles (e.g., wind/hail percentages) that are not fully represented by the simple factors here.

How to verify or improve accuracy

1. Source a current benchmark for homeowners premiums by state (e.g., public regulatory summaries or industry reports).
2. Convert those to relative factors (state ÷ national) and save as /data/state-multipliers.json with an updated date.
3. Re‑test a few scenarios against quote ranges from multiple carriers or agents; adjust only the state factors (not the user‑visible multipliers) to stay consistent.

Privacy & data handling

Calculations run in your browser; we do not transmit your inputs to a backend. We use Google Analytics and AdSense and respect your consent preferences (Consent Mode v2). See Privacy for details.

Contact & feedback

Questions, corrections, or data you'd like us to review? Email everydayroyalties@gmail.com.