Radon Mitigation Cost Calculator
How much does radon mitigation cost? This radon mitigation cost calculator estimates a low–high price range for a radon reduction system from your home's foundation size, foundation type, measured radon level, and the mitigation method you plan to use.
Enter your numbers
Ground-floor footprint of the foundation (length × width), not total living area.
Your most recent short-term or long-term test result. EPA action level: 4.0 pCi/L.
Your results
| Midpoint (estimate) | – |
|---|---|
| Low end | – |
| High end | – |
| System | – |
How to use this calculator
Start with your foundation footprint in square feet — the ground-floor area of the foundation, not your home's total living space. For a rectangular home this is simply length times width. Then pick your foundation type (basement, slab-on-grade, or crawl space), since crawl spaces need membrane sealing and cost more to treat.
Enter your radon level in pCi/L from your most recent test. The U.S. EPA recommends fixing your home if it tests at or above 4.0 pCi/L, and the calculator adds a severity surcharge for higher readings, since higher radon levels often call for a larger fan or more suction points.
Choose the mitigation method: active sub-slab depressurization is the standard for existing homes; crawl-space membrane adds sealing work; a passive system is only realistic during new construction (and is cheaper); multiple suction points cost more for large or complex footprints. Results update instantly as you change anything — and remember the output is an estimate to sanity-check real contractor quotes.
How it works
The calculator starts from published national-average figures: the EPA and the National Radon Proficiency Program (NRPP) put the cost of radon mitigation at roughly $800–$2,500, with a typical active sub-slab system in an average basement running about $1,200. That $1,200 base covers a ~1,000 sq ft basement footprint.
From there the estimate is adjusted:
| Adjustment | How it's applied |
|---|---|
| Home size | + $0.40 per sq ft of footprint above 1,000 sq ft |
| Foundation type | × 1.00 basement · × 1.05 slab-on-grade · × 1.25 crawl space |
| Mitigation method | × 1.00 sub-slab depressurization · × 1.20 crawl-space membrane · × 0.60 passive during construction · × 1.25 multiple suction points |
| Radon severity | + $25 per pCi/L above the EPA action level of 4.0 pCi/L |
| Estimate range | ± 20% around the midpoint (low = × 0.80, high = × 1.20) |
In formula form: midpoint = ($1,200 + $0.40 × max(sqft − 1,000, 0)) × foundation factor × method factor + $25 × max(pCi/L − 4.0, 0), rounded to the nearest $50. The low end is 80% of the midpoint and the high end is 120%, also rounded to $50.
Assumptions and limits. These are planning estimates, not quotes. The model assumes a straightforward install by a certified mitigator; local labor rates, accessibility of your slab or crawl space, electrical work, and finished basements that need cosmetic repair can all move the real price outside this range. For example: a 1,500 sq ft basement with 8.0 pCi/L using standard sub-slab depressurization estimates at ($1,200 + 500 × $0.40) × 1.00 × 1.00 + $25 × 4 = $1,500 midpoint, or a $1,200–$1,800 range. Always get 2–3 written quotes from NRPP- or NRSB-certified mitigators before committing.
Frequently asked questions
How much does radon mitigation cost?
According to EPA and National Radon Proficiency Program (NRPP) figures, the national average cost of a radon mitigation system is roughly $800 to $2,500, with a typical active sub-slab system costing about $1,200 for an average basement. Larger homes, crawl spaces, and complex installs run higher. These are national averages — get quotes from local certified mitigators for an exact price.
What radon level requires mitigation?
The U.S. EPA sets 4.0 pCi/L as the action level: if your home tests at or above 4.0 picocuries per liter, the EPA recommends installing a mitigation system. For levels between 2.0 and 4.0 pCi/L, the EPA suggests considering mitigation since there is no known safe level of radon exposure.
What is sub-slab depressurization?
Sub-slab depressurization is the most common active radon mitigation method. A contractor drills one or more suction pits through the slab, connects PVC piping to an inline fan, and vents the radon-laden air above the roof. It typically takes 4–8 hours to install and is included as the standard method in this calculator.
Are these cost estimates exact?
No — they are planning estimates built from national-average cost figures. Real prices vary with local labor rates, your home's layout, accessibility of the slab or crawl space, and how high your radon levels are. Use this calculator to sanity-check quotes, then get 2–3 written quotes from NRPP- or NRSB-certified mitigators.
How long does radon mitigation installation take?
Most residential radon mitigation systems are installed in a single day, usually 4 to 8 hours of work. A follow-up radon test 24–48 hours after installation confirms the system is working, and the EPA recommends retesting your home every two years afterward.