Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Estimated total damage
$145,250
Structural damage estimate
$105,000
Contents damage estimate
$40,250
Structural damage %
35%
Out-of-pocket (deductible)
$2,000
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How to use this
- 1Enter flood depth above first floor (ft).
- 2Enter home replacement value ($).
- 3Enter contents value ($).
- 4Enter insurance deductible ($).
- 5Read your estimated total damage on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
Flood damage doesn't scale linearly with water depth — the first inch of water in a home (soaking flooring, drywall, and baseboards) often causes a disproportionate share of total damage, while additional feet add damage at a slower marginal rate until contents and systems above the waterline are also submerged. This calculator applies simplified depth-damage percentage curves similar in shape to those FEMA and the Army Corps of Engineers use in flood risk studies, scaled to your home's replacement value and contents value. It's meant for rough budgeting and insurance conversation prep, not a substitute for a professional adjuster's on-site assessment, which accounts for water contamination level, duration of standing water, and construction type.
Worked example
Using the values the calculator loads with:
Inputs
- Flood depth above first floor: 2 ft
- Home replacement value: 300000 $
- Contents value: 100000 $
- Insurance deductible: 2000 $
Results
- Estimated total damage: $145,250
- Structural damage estimate: $105,000
- Contents damage estimate: $40,250
- Structural damage %: 35%
- Out-of-pocket (deductible): $2,000
What each field means
Inputs
- Flood depth above first floor (ft)
- The flood depth above first floor used in the calculation, measured in ft. Starts at 2 ft so you have a working example on load. Accepted range: -2–12 ft.
- Home replacement value ($)
- The home replacement value used in the calculation, measured in $. Starts at 300000 $ so you have a working example on load.
- Contents value ($)
- The contents value used in the calculation, measured in $. Starts at 100000 $ so you have a working example on load.
- Insurance deductible ($)
- The insurance deductible used in the calculation, measured in $. Starts at 2000 $ so you have a working example on load.
Results
- Estimated total damage
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Structural damage estimate
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Contents damage estimate
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Structural damage %
- Returned as a percentage. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Out-of-pocket (deductible)
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why does even a small amount of water cause so much damage?
The first inches of floodwater saturate drywall, flooring, insulation, and baseboards throughout the entire footprint of the home, which is most of the reason depth-damage curves front-load a big damage percentage at shallow depths before flattening out at deeper levels.
Does homeowners insurance cover flood damage?
Standard homeowners policies exclude flood damage almost universally in the US. You need a separate policy, either through the National Flood Insurance Program (NFIP) or a private flood carrier, and NFIP policies cap building coverage at $250,000 and contents at $100,000 for residential properties.
How accurate are depth-damage curves for a specific house?
They're regional and construction-type averages, not predictions for your exact home. Elevated homes, homes with flood vents, finished vs. unfinished basements, and contaminated (vs. clean) floodwater all shift real damage meaningfully above or below the curve estimate.
What single step reduces flood damage the most?
Elevating utilities (HVAC, water heater, electrical panel) above the base flood elevation prevents the most expensive system replacements, since HVAC and electrical damage from flooding often exceeds the cost of flooring and drywall combined.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Flood Depth-Damage Cost Estimator. Retrieved from https://www.revenuelab.fyi/toolbox/flood-depth-damage-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/flood-depth-damage-cost" target="_blank" rel="noopener">Flood Depth-Damage Cost Estimator — RevenueLab</a> (2026).</p>
Source: [Flood Depth-Damage Cost Estimator — RevenueLab](https://www.revenuelab.fyi/toolbox/flood-depth-damage-cost) (2026).