Storm shelter calculator: size and price for your household

Enter how many people need to fit and the kind of shelter you want. The calculator shows the FEMA minimum floor space, the published 2026 price band for the closest size, and the city permit fee where we have one. It is an estimate, not a quote.

Where these numbers come from

The floor space rule is FEMA's tornado minimum of 3 square feet of usable floor space per person in a one- or two-family home (FEMA P-320 (2025)). The price bands are the published 2026 table from okctornadoshelters.com, which lists 4, 6, 10 and 14 person sizes for above-ground safe rooms, underground concrete shelters and garage in-floor steel shelters. The calculator picks the smallest listed size that fits everyone. All of these figures are on our storm shelter costs page.

Permit fees come from the city pages linked on that page: Oklahoma City charges $99.50 for in-ground or slope-top shelters and $104.50 for an above-ground safe room, Edmond charges $35, and Norman charges $50, or $54.50 with the state fee.

What the calculator cannot know

Soil, access, the door model and options like ramps, fans and lights all change the price. The same 2026 source says most OKC installs fall between $3,000 and $12,000, and that a quality shelter door can cost $1,500 or more by itself. Some outdoor underground shelters in OKC also need an engineer flotation letter. Get a site visit before you sign, because a phone quote cannot see your soil or your garage slab.

The SoonerSafe rebate is not open for 2026, so do not count on it in your budget. See our rebate status page.

Sending your estimate

The button under your result opens our quote form with the shelter type, household size, town, ZIP and price band already filled in. You add your name and phone. We are an independent guide, not an installer, and we pass the request to a local installer.

Last checked Nov 2, 2026. Estimates only, not quotes, not engineering or legal advice.