Free radon tool

Radon Test Result Checker

Got a radon number back from a test kit, a home inspector or a continuous radon monitor? This checker puts it in context. It converts your result to Bq/m³, shows how it compares to the EPA and WHO levels, and estimates how much a mitigation system would need to lower it.

Reduction Needed to Reach Target

68%

Times the EPA Action Level: 1.55
Result in Bq/m³: 229

At or above the EPA action level of 4.0 pCi/L. The EPA recommends mitigation. If this number came from one short-term test, confirm it with a follow-up test or move straight to a fix.

Unit conversion (1 pCi/L = 37 Bq/m³), ratio to the EPA 4.0 action level, and percent reduction needed to reach the chosen target.

Above 4.0 pCi/L? Let's Fix It

Send your result and foundation type and we'll recommend the right system.

The math

How the Test Result Checker Works

01
Unit conversion

US test reports use picocuries per liter (pCi/L). Most other countries and the WHO use becquerels per cubic meter (Bq/m³). One pCi/L equals 37 Bq/m³.
02
EPA action level

The EPA recommends fixing a home at 4.0 pCi/L or higher. We divide your result by 4.0 to show how many times over that line you are.
03
Reduction needed

We compare your result to the target you pick and show the percent drop needed to reach it. A properly installed active system typically brings levels below 4.0 pCi/L, and often below 2.0.

Good to know

Test Result Checker Questions

What is a safe radon level?

No level of radon is risk-free. The EPA recommends fixing your home at 4.0 pCi/L or higher and suggests considering a fix between 2.0 and 4.0 pCi/L. The WHO reference level is 100 Bq/m³, about 2.7 pCi/L.

Should I trust one short-term test?

A 2- to 7-day test is a snapshot. Radon changes with weather and season, so the EPA suggests a follow-up test before deciding, unless you're on a real estate deadline. A long-term test of 90 days or more gives the best year-round average.