Radon Test Calculator
Schedule a radon test window, keep it inside the heating season when possible, and compare a lab result with the Health Canada guideline.
A long-term radon test started October 1 runs through 2026-12-31; a 240 Bq/m3 result is above the Canadian guideline and should follow Health Canada action guidance.
How to use it
- Choose a test type. Use a long-term test for the main schedule, or a short-term test for quick screening.
- Pick the start date. Choose when the detector will be placed in the lowest lived-in level of the home.
- Add the lab result if you have it. Enter the Bq/m3 result only after the lab report comes back.
- Read the schedule and guideline note. Use the test window, retest reminder, and Health Canada action wording as planning guidance.
How this works
The calculator uses 91 days for a long-term test, 7 days for a short-term screen, and October through April as the heating-season target window. It then sets a 5-year retest reminder and compares any entered result with the Canadian guideline.
Sources
Radon test length, heating-season retest advice, the 200 Bq/m3 guideline, and current corrective-action timing follow Health Canada's residential radon measurement guide and Health Canada's radon guideline page. Use the lab report and a certified radon professional for mitigation decisions.
Radon test questions
When should I start a radon test?
For a long-term home test, start during the heating season when the house is more closed up. Health Canada uses at least 91 days for a valid long-term residential result.
What radon level triggers action in Canada?
The Canadian radon guideline is 200 Bq/m3. Health Canada currently recommends mitigation within 1 year above that level, and sooner when the level is higher.
Can a short-term radon test decide whether to remediate?
A short-term test can screen for a possible issue, but Health Canada says corrective action decisions should be based on tests of at least 91 days.
How often should I retest for radon?
Retest after major renovations, energy retrofits, excavation near the home, mitigation work, or about every 5 years for ongoing checks.
Does this calculator diagnose health risk?
No. It schedules testing and compares a lab result with the Canadian guideline. It does not diagnose exposure, illness, or individual risk.