Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Est. water depth at property (ft)
3.0
Total surge + wave water level
11.0
Risk category
Severe flooding expected
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How to use this
- 1Enter property elevation above sea level (ft).
- 2Enter forecast storm surge height (above ground) (ft).
- 3Enter additional wave action allowance (ft).
- 4Read your est. water depth at property (ft) on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Storm surge is the abnormal rise of seawater pushed onshore by a hurricane's winds and low pressure, and it's historically the deadliest hazard in tropical cyclones, responsible for the majority of direct hurricane fatalities in events like Katrina and Ike. This calculator compares your property's ground elevation against a forecast surge height (from NHC advisories, typically given as feet above ground level, AGL) plus expected wave action on top of the surge, to estimate how much water, if any, would reach your property and by how much it would exceed your elevation. Always use official National Hurricane Service surge forecasts and local evacuation zone maps for actual safety decisions — this tool is for understanding the arithmetic behind those warnings, not for real-time evacuation planning.
Worked example
Using the values the calculator loads with:
Inputs
- Property elevation above sea level: 8 ft
- Forecast storm surge height (above ground): 9 ft
- Additional wave action allowance: 2 ft
Results
- Est. water depth at property (ft): 3
- Total surge + wave water level: 11
- Risk category: Severe flooding expected
What each field means
Inputs
- Property elevation above sea level (ft)
- The property elevation above sea level used in the calculation, measured in ft. Starts at 8 ft so you have a working example on load. Accepted range: -5–50 ft.
- Forecast storm surge height (above ground) (ft)
- The forecast storm surge height (above ground) used in the calculation, measured in ft. Starts at 9 ft so you have a working example on load. Accepted range: 0–25 ft.
- Additional wave action allowance (ft)
- The additional wave action allowance used in the calculation, measured in ft. Starts at 2 ft so you have a working example on load. Accepted range: 0–10 ft.
Results
- Est. water depth at property (ft)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total surge + wave water level
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Risk category
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What's the difference between storm surge and storm tide?
Storm surge is the rise in water level caused purely by wind and pressure from the storm. Storm tide is storm surge combined with the normal astronomical tide at the time of landfall — a surge arriving at high tide can push water significantly higher than the same surge at low tide.
Where do I find my property's actual elevation?
FEMA flood maps, USGS topographic data, and many county GIS property lookup tools show ground elevation relative to a standard datum (usually NAVD88). Surge forecasts from the National Hurricane Center are typically given relative to ground level, so make sure your elevation source matches the datum being used.
Why include a wave action allowance separately from surge?
Storm surge forecasts represent the still-water level, but wind-driven waves on top of that elevated water add additional dynamic height and impact force, especially for oceanfront and immediate coastal structures — FEMA flood zone V designations specifically account for this extra wave hazard.
Should I use this tool instead of official evacuation orders?
No — always follow local emergency management evacuation orders and official NHC storm surge watch/warning products. This calculator illustrates the underlying arithmetic for educational purposes; official forecasts incorporate storm track uncertainty and local bathymetry that a simple calculator cannot.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Storm Surge Elevation Risk Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/storm-surge-elevation-risk
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/storm-surge-elevation-risk" target="_blank" rel="noopener">Storm Surge Elevation Risk Calculator — RevenueLab</a> (2026).</p>
Source: [Storm Surge Elevation Risk Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/storm-surge-elevation-risk) (2026).