How this estimator works — and what it is not
This is a dwelling-coverage estimator, not a premium quote. Premiums are insurer underwriting — your roof's age, your ZIP code's hail history, your claims record, your deductible — and no honest calculator can predict them. What we can estimate is the number that drives the whole coverage conversation: Coverage A, the cost to rebuild your house from the foundation up at today's construction prices. Get that number roughly right and everything else in the policy (personal property, loss of use) follows from it, because insurers set those limits as percentages of Coverage A.
The per-square-foot rates come from published 2026 national construction data: Angi's rebuild-cost guide puts typical bands near $165/sq ft for basic tract construction, $230 for standard, and $320 for custom, and NAHB builder surveys average about $162/sq ft nationally. We round to clean rates of $160 / $220 / $320 and show the result as a ±15% range, because pretending to more precision than that would be lying to you.
The formula
Square footage is finished living area; cost per sq ft is $160 (basic), $220 (average), or $320 (custom); the garage factor is 1.08 if you have an attached garage — the midpoint of the common 5–10% rule of thumb, since garage space is cheaper to build than living space but still burns down with the house. Personal property is 50–70% of Coverage A and loss of use about 20%, the standard structure of a US homeowners policy.
Worked example
A 2,000 sq ft home of average construction with an attached garage: 2,000 × $220 = $440,000, times 1.08 for the garage = a point estimate of $475,200. With ±15% rounded outward to clean numbers, the estimated dwelling coverage is $400,000 – $550,000.
From that point estimate, personal property at 50–70% is roughly $237,000 – $333,000, and loss-of-use coverage at ~20% is about $95,000. Liability isn't a percentage — $300,000 to $500,000 is the commonly recommended range.
The land doesn't burn: rebuild cost vs market value
The single most useful thing to understand about home insurance: your Coverage A has nothing to do with what your house would sell for. Market value bundles the structure with the land and the location premium — and the land survives any disaster. A $750,000 bungalow in a coastal metro might cost $350,000 to rebuild; a grand 1920s foursquare in a small town might sell for $250,000 but cost $450,000 to reconstruct with anything resembling its original millwork. Insure to market value and you're either paying for coverage you can never use or — far worse — standing in the ashes 40% short.
Why underinsurance happens (and the 80% rule)
Industry studies consistently find that 10–25% of US homes are underinsured against their true rebuild cost. The mechanism is quiet: you set Coverage A when you buy the policy, then construction costs inflate 4–8% a year while your limit sits still. Five years later you're 25% short and nobody sent a memo. This matters even for partial losses because of the 80% rule: if your coverage falls below 80% of full replacement cost, many policies pay even small claims proportionally rather than in full. Two defenses: review Coverage A annually against current $/sq ft, and ask about an extended replacement cost endorsement (typically +25–50% above your limit) — it's cheap and it's exactly the buffer that saves people after a regional disaster spikes local construction prices.
What actually moves your premium
Since this tool won't quote you a premium, here's what will move the one your insurer quotes: location risk (hail, hurricane, wildfire — the dominant factor, and why identical houses can differ 3× between states), roof age and material (many insurers now surcharge or refuse roofs over 15–20 years old), your deductible (raising $1,000 to $2,500 commonly cuts 10–15%), claims history (even a single claim can follow you for 3–5 years), and credit-based insurance score in most states. The dwelling limit itself matters less than people expect — which is exactly why trimming Coverage A to save on premium is a terrible trade.