Building an estimate from the inputs
Enter the home's floor area and a per-square-foot rebuilding cost obtained for the relevant location and construction type. This cost is user supplied: the calculator has no local cost database and does not infer a figure from a sale price. Other structures and features are entered as one additional amount so you can include items outside the basic square-foot estimate. Do not include land value.
The dwelling limit is the amount shown in your policy for the residence. The required percentage is a policy term; the example starts at 80 percent because many policies use that figure, but you should read your own contract and replace it with its stated requirement. Sample loss is only a scenario amount. The deductible is entered separately.
Formula and worked scenario
Estimated replacement cost equals square feet multiplied by rebuild cost per square foot, plus extras. Required limit equals that replacement estimate times the percentage. Shortfall is the larger of zero or required limit minus current dwelling limit. For this page’s simplified sample, the carried-to-required ratio is capped at one. Sample payout is the smaller of the current limit and the greater of zero or (sample loss times that ratio minus deductible). The amount you would bear is sample loss minus estimated payout, floored at zero.
For example, imagine 1,800 square feet at $220 per square foot and $20,000 in extras. Estimated replacement cost is $416,000. At an 80% requirement, the required limit is $332,800. A $350,000 limit has no shortfall under this arithmetic. With a $80,000 sample loss and $1,000 deductible, the ratio is one, so the sample payout is $79,000 and the amount borne is $1,000. Those fictional numbers demonstrate multiplication only; they do not describe a typical home or policy.
Limits of the coinsurance example
Loss settlement language differs. Some forms use replacement-cost provisions, conditions, limits, exclusions, or formulas that do not match this illustration. The tool also assumes the sample loss is covered and does not account for sublimits, ordinance or law expenses, depreciation, prior damage, claim adjustment, inflation provisions or recoverable depreciation. A calculated shortfall is not proof that a carrier will apply a penalty.
Purchase price and mortgage balance are not the same as rebuild cost: land is not rebuilt, and labor, materials, design, bathrooms, roof, exterior, special features and local building practices can affect reconstruction. A rough area-times-cost multiplication can miss custom work or code upgrades. Triple-I discusses rebuilding considerations and ways to think about dwelling coverage; obtain a property-specific estimate for decisions.
Ways to make the scenario useful
Change one input at a time and record its source. If you adjust the requirement percentage, note the policy section that supplies it. If you vary the rebuild cost, use a few explicitly labeled estimates from credible local sources rather than treating the calculator default as evidence.
Ask the insurer whether the policy includes extended or guaranteed replacement cost, inflation guard, ordinance or law coverage, and any special settlement rules. Review separate wind, hail, flood or earthquake terms where relevant. State laws and policy wording vary, and flood or earthquake protection can be separate coverage.
Scope and limitations
The figures are educational estimates based on your entries, not insurance, legal, tax or financial advice. ClaimCheck is an independent publisher and is not an insurer, agent, adjuster or law firm. Policy language and state requirements differ; verify coverage directly. Flood and earthquake are separate coverages.