You can buy a radon test kit at a hardware or home improvement store or online, order a discounted kit from Kansas State University’s EPA-funded radon program, or get one free or cheaply through your state (EPA; CDC). A short-term kit is the place to start.
Your options
Home improvement and hardware stores. Many stores, including the big home improvement chains such as Home Depot, Lowe’s and Menards, stock do-it-yourself radon kits. EPA and CDC both list stores as a normal place to buy one.
Online. Kits are sold online by labs, retailers and marketplaces such as Amazon. Buy one that is analyzed by a qualified laboratory (EPA, Consumer’s Guide to Radon Reduction).
National Radon Program Services (Kansas State University). This program runs under a cooperative agreement with EPA. As of November 2026 its short-term kits (2 to 4 days) cost $20 and its long-term kits (3 to 12 months) cost $30, and both prices include the lab analysis and return (sosradon.org). You can also order by phone at 1-800-SOS-RADON (767-7236).
Your state radon program. Some states give away or discount kits. Your state radon program can tell you what’s on offer, and can point you to a radon measurement professional (EPA).
A professional tester. If you’re buying or selling a home, or would rather not do it yourself, you can hire a qualified radon tester. See radon inspections.
What to check before you buy
- Is the lab fee included? Some kits include the lab analysis and return postage; others charge for it separately. Compare the total cost.
- Short-term or long-term? Start with a short-term test (2 to 90 days). A long-term test (more than 90 days) gives a better picture of your year-round level (EPA, Consumer’s Guide). See how to test for radon.
- How fast must it reach the lab? Charcoal kits have to be mailed soon after the test ends. For the Kansas State short-term kit, the lab must receive it within 10 days of the end of the test for the result to be accurate (sosradon.org).
- State rules. Some states have their own requirements. For example, New Jersey charges a state fee on short-term kits analyzed for homes there (sosradon.org).
- A kit or a monitor? Passive kits are cheap and sent to a lab. Electronic continuous monitors cost more, need power, and show hourly readings (EPA, Consumer’s Guide).
After you buy
Follow the instructions in the kit, test in the lowest lived-in level of your home, and mail it promptly. If your result is 4 pCi/L or more, do a follow-up test, then read how radon mitigation systems work. To see how often tests near you come back high, look up your county below.