Coinsurance Penalty Calculator: Are You Underinsured?
Check whether your property limit meets the coinsurance clause and estimate what you'd actually collect after the underinsurance penalty and deductible.
Reviewing the policy itself? Get a clause-by-clause read with Insurance Policy Review.
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How to use this coinsurance calculator
- Enter your property's value at the time of loss (the figure your policy is measured against).
- Set the coinsurance requirement (usually 80%, 90%, or 100%) and the limit you actually carry.
- Enter the loss amount and your deductible to see the penalty and your estimated payout.
The required limit is property value × coinsurance percentage. If the limit you carry is below that, the insurer pays only the carried-over-required share of the loss.
How to avoid a coinsurance penalty
- Insure to value: Carry at least the required percentage of an accurate, current property value.
- Re-check as values rise: Construction costs and reassessments can push you below the threshold over time.
- Ask about agreed value: An agreed-value or waiver-of-coinsurance endorsement suspends the coinsurance test for the term.
- Confirm the valuation basis: Replacement cost vs. actual cash value (ACV) changes both the required limit and the payout.
- Mind blanket limits and sublimits: They can change how the clause is applied across locations or perils.
See how coinsurance and other property clauses are worded in the Clause Library.
Coinsurance calculator FAQs
BizLeaseCheck provides informational analysis and is not legal or insurance advice.