Radon Compass

Is radon high where you live?

Real test results from 1.4 million homes, for all 3,143 US counties and 1,904 zip codes, and what fixing high radon actually costs.

ExampleLancaster County, Pennsylvania
43,005 homes tested
  • Below 2 pCi/L: 39%
  • 2 to 4 pCi/L: 18%
  • 4 pCi/L or more: 43%
The line marks the EPA action level, 4 pCi/L.
About 4 in 10 homes tested here were at or above the EPA action level. Fixing it typically costs $1,345.

Fixing radon costs less than most people think

From 35,413 radon systems installed in Pennsylvania homes since 2021, as reported to the state.

$1,295

Typical price for a standard system. Half paid between $1,100 and $1,495.

7.7 → 1.0

Typical radon level in pCi/L before and after a system was installed.

95%

of fixed homes ended up below the EPA action level of 4 pCi/L.

See what fixing radon costs in your county

What to do about radon

  1. Test your home

    Neighboring houses can differ a lot. A 2 to 7 day test kit in your lowest lived-in floor is the first step.

  2. Know what your number means

    Below 2 pCi/L is low. Between 2 and 4, the EPA says to consider fixing. At 4 or more, the EPA recommends fixing your home.

  3. Fix it with a certified pro

    A certified professional installs a pipe and a quiet fan, usually in a day. Look up your county for local costs.

Browse by state

Share of homes tested at or above 4 pCi/L, lab data 2008–2017.