Professional services
Flood Insurance Calculator
Works flood cover, which standard property policies do not include.
Result
An estimating tool, not insurance advice and not a quote. Underwriting sets real premiums on factors no calculator sees. What cover is appropriate is a question for a licensed broker. Flood is excluded from every standard homeowners policy. Cover comes through the national programme or private insurers, and programme limits cap building and contents cover well below the value of many homes, with excess flood cover needed above that. Most policies carry a waiting period before cover starts, so buying as a storm approaches does not work. Roughly a quarter of flood claims come from outside high-risk zones.
Get a Free Business AuditHow the calculation works
Building and contents coverage amounts at rates reflecting flood zone, elevation and construction, with the deductible chosen, giving annual and monthly cost. Flood is excluded from standard homeowners and commercial property policies and has to be bought separately, through the National Flood Insurance Program or private carriers.
What moves the number
- Flood zone and the property's elevation relative to base flood elevation.
- Building and contents coverage amounts.
- Deductible chosen.
- Construction type and whether there is a basement.
Where this one goes wrong
Most flood claims nationally arise outside the highest-risk zones, which means a property not required to carry flood cover is not thereby safe, and the premium outside high-risk zones is correspondingly lower. The other point is the coverage structure: contents are separate from building cover and basements are treated restrictively, so a policy bought for the building alone can leave most of the actual loss uncovered. There is also usually a waiting period before cover starts, which rules out buying as a storm approaches.
Before you quote
- Check the waiting period, since cover does not start immediately.
- Buy contents cover separately from building cover.
- Understand how basements are treated before relying on the policy.
Where the rules come from
Questions
About this calculator
Does my homeowners policy cover flood?
No. Flood is excluded from standard homeowners and commercial property policies and has to be bought separately, through the National Flood Insurance Program or a private carrier. Discovering that after a loss is unfortunately common.
Do I need flood cover outside a high-risk zone?
A substantial share of flood claims nationally arise outside the highest-risk zones, so not being required to carry it does not mean the risk is absent. The premium outside high-risk zones is also much lower, which changes the calculation.
Can I buy flood cover when a storm is coming?
Generally not usefully, because there is typically a waiting period before cover starts. That is deliberate, and it means the decision has to be made in ordinary weather rather than when the forecast makes it feel urgent.
The formula
premium = cover / 1000 x base rate x zone factor x elevation factor, less deductible credit
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How to use this calculator
- Building cover ($). Enter your own figure; the page starts at $250,000.
- Contents cover ($). Enter your own figure; the page starts at $100,000.
- Flood zone. Enter your own figure; the page starts at Zone AE, 1% annual chance (1.0x).
- Feet above base flood elevation. Enter your own figure; the page starts at 1.
- Deductible ($). Enter your own figure; the page starts at $2,000.
- Base rate per $1,000. Enter your own figure; the page starts at 3.2.
The result updates as you type, so you can try a figure, see what it does to estimated annual premium, and change it back. Nothing you enter is sent anywhere or saved.
A worked example
These are the figures the calculator opens with. Every number in the results column below is produced by the same calculation the page runs, so you can follow it through before putting your own figures in.
What goes in
| Input | Value |
|---|---|
| Building cover | $250,000 |
| Contents cover | $100,000 |
| Flood zone | Zone AE, 1% annual chance (1.0x) |
| Feet above base flood elevation | 1 |
| Deductible | $2,000 |
| Base rate per $1,000 | 3.2 |
What comes out
| Result | Value |
|---|---|
| Estimated annual premium main result | $810.48 |
| Per month | $67.54 |
| Effect of elevation | -22.0% |
| Total cover | $350,000 |
| Cost per $1,000 of cover | $2.32 |
About $810.48 a year for $350,000 of cover in zone AE. Being 1 feet above base flood elevation changes the premium by -22.0%, which is why an elevation certificate is worth obtaining.
How sensitive the answer is
Holding everything else steady and changing only building cover, this is what happens to estimated annual premium. It is worth knowing which of your inputs the answer actually hinges on, and which barely move it.
| Building cover ($) | Estimated annual premium |
|---|---|
| $125,000 | $521.03 |
| $187,500 | $665.76 |
| $250,000 example above | $810.48 |
| $375,000 | $1,100 |
| $500,000 | $1,389 |
Every other input is held at the example value while this one changes, which is not how a real job behaves. Treat it as a guide to which number matters most, not as five separate quotes.
What each figure means
- Building cover ($)
- A money amount, starting at $250,000.
- Contents cover ($)
- A money amount, starting at $100,000.
- Flood zone
- Choose from Zone X, minimal risk (0.35x), Zone AE, 1% annual chance (1.0x), Zone A, no base elevation (1.3x), Zone VE, coastal wave action (2.6x).
- Feet above base flood elevation
- A number, between -10 and 20, starting at 1.
- Deductible ($)
- A money amount, starting at $2,000.
- Base rate per $1,000
- A number, between 0 and 40, starting at 3.2.
What the results tell you
| Result | What it is |
|---|---|
| Estimated annual premium | The headline result. A money figure. |
| Per month | A money figure. |
| Effect of elevation | A percentage. |
| Total cover | A money figure. |
| Cost per $1,000 of cover | A money figure. |
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