What does my radon result mean?
Your number is for the test you ran, in that spot, over those days. A short-term kit is an accurate snapshot. A snapshot is not a pattern.
Under about 1.5
Low. A reading such as 0.8 or 1.2 fits here. Retest in a couple of years, or after big renovations.
About 1.5 to 2
Close to the 2.0 line. A reading such as 1.7 fits here. Radon levels shift with the seasons. Retest in winter, or watch it with a monitor.
2 to 4
The EPA says to consider fixing in this range. A reading such as 2.6 or 3.2 fits here. One snapshot cannot tell you whether this was a high week or your normal. A monitor shows a month of readings so you can tell.
Bill's pick: Airthings Corentium Home 2, $179.99 when we checked on October 1, 2026.
If you buy through our Airthings link, we may earn a commission. You don't pay extra. Add your name and shipping, then enter ARS10-10OFF. The link does not apply the code by itself.
4 and over
Fix it. A reading such as 4.0 or 8 fits here. Hire someone licensed where the house is. This page does not route you to a contractor yet. Start with your state radon program and ask how to find a licensed mitigator.
- Colorado Department of Public Health and Environment
- Illinois Emergency Management Agency and Office of Homeland Security
- Indiana Department of Health
- Iowa Health and Human Services
- Kansas Department of Health and Environment
- Massachusetts Department of Public Health
- Michigan Department of Environment, Great Lakes, and Energy
- Minnesota Department of Health
- Missouri Department of Health and Senior Services
- Montana Department of Environmental Quality
- Nebraska Department of Health and Human Services
- New Hampshire Department of Health and Human Services
- New York State Department of Health
- North Dakota Department of Environmental Quality
- Ohio Department of Health
- Pennsylvania Department of Environmental Protection
- South Dakota Department of Agriculture and Natural Resources
- Wisconsin Department of Health Services
If your state is not in that list, use EPA's page for finding a test kit or a measurement and mitigation professional.
If you already have a mitigation system
Watch your system work. A monitor lets you see what the level does after the fan is running, instead of guessing from one old test.
If you buy through our Airthings link, we may earn a commission. You don't pay extra. Add your name and shipping, then enter ARS10-10OFF. The link does not apply the code by itself.
One state's follow-up steps, kept as their own page: understanding radon results. The action level, on its own page: what 4 pCi/L means.