Radon Mitigation Cost Calculator

The EPA does not publish radon mitigation costs

This is the first thing to establish, because EPA-attributed radon prices are everywhere and most of them are stale. The 2025 edition of EPA's Consumer's Guide to Radon Reduction (EPA 402/K-10/005) carries a full-page table on page 16 headed “Radon Reduction of Various Mitigation Techniques”, with a row for every method a contractor might propose. Its two columns are Typical Radon Reduction and Comments. There is no cost column, and the note printed beneath the table says only this:

“Mitigation costs vary due to technique, materials, and the extent of the problem. Typically the cost of radon mitigations are comparable to other common home repairs.”

Earlier editions of the same booklet did carry installation and annual operating cost columns, and figures lifted from them still circulate as though they were current federal guidance. They are not in the 2025 edition, so they are not quoted here as EPA figures. The only dollar amount in the entire booklet is $10–$25 for replacement HRV filters — which is a useful tell that the silence on system cost is editorial rather than a gap in what EPA knows.

So the division of labour on this page is clean. EPA supplies the action level, the effectiveness percentages, the retest protocol, the foundation-to-technique mapping and the service-life guidance. A cost publisher supplies the dollars. Neither is asked to do the other's job, and every figure says which one it came from.

What EPA does publish: how well each technique works

This is EPA's page-16 table, reproduced in full. Read it as the answer to a question a cost table cannot answer — not “what will this cost” but “will this work”. The two rows worth comparing before you sign anything are the first two.

Note what EPA says about sealing, which is the cheapest thing anyone will offer you: it is “normally only used with other techniques”, and elsewhere in the booklet EPA states plainly that it “does not recommend the use of sealing alone to reduce radon” because by itself it “has not been shown to lower radon levels significantly or consistently”. A quote for sealing only is not a mitigation system.

The two published cost bands, and the third figure that disagrees with both

HomeAdvisor's page, updated 19 June 2026, is the cost backbone here and it contains three different answers to “how much”. All three are printed below, because reconciling them into a fourth number nobody published is the overclaim this site refuses.

The tension is real and worth naming. The member average of $1,028 sits at the very bottom of the $1,000–$3,000 active-suction band, even though EPA calls active subslab suction the most common method — and the $2,453 “large or complex” ceiling sits below the same page's $3,000 active-suction top end. The reading that makes all three consistent is mix: the member figures describe the ordinary job, and the system-type bands describe the whole market including the complex end. This calculator prices from the system band, because it is the finer instrument, and shows the member range as a cross-check that never touches the total.

Nobody independent prices a suction point

The suction-point count is the biggest single driver of a real radon quote, and it is the one figure this calculator deliberately refuses to multiply by. That refusal needs explaining rather than hiding.

EPA describes how the count is decided — it “depends on how easily air can move in the crushed rock or soil under the slab and on the strength of the radon source” — and then says something reassuring that most cost pages omit: “Often, only a single suction point is needed.” That is why the slider on this page starts at one. It attaches no price to a point.

Per-point figures are easy to find. Every instance located on 11 September 2026 traced back to a radon mitigation contractor's own marketing page — a company publishing the price of its own upsell. This site does not accept a vendor page as the sole source for a constant it would then multiply by, because the resulting number looks like a measurement and is a quote. So the published band is reported at full width, and the honest version of your per-point cost is the itemised line you ask your mitigator to put on the quote.

The same reasoning removes the per-square-foot rate. Slab area is asked because it bears on whether one suction point is plausible; it is multiplied by nothing. EPA does name the case most likely to need several: a house with more than one foundation type, where “a combination of radon reduction techniques may be needed”.

The retest is not optional, and not the installer's to do alone

EPA's contractor checklist asks for a post-mitigation test within 30 days of installation, but no sooner than 24 hours after the system is running with the fan on. It then adds the part worth reading twice: although many contractors will test their own work, EPA recommends you also arrange an independent follow-up measurement, because doing so “will eliminate any potential conflict of interest”. It suggests a two- to seven-day measurement, with windows and doors closed for 12 hours before and during the test.

That measurement is $150–$800 — the same band as the pre-work professional test, because it is the same measurement performed again, and inventing a second number for it would be inventing. EPA also advises retesting the house at least every two years afterwards, and after any major structural change, to confirm levels have stayed low.

Two things on radon quotes that are not radon systems

Both are on the calculator's add-on list because both genuinely appear on radon quotes, and both are flagged on the results as separate jobs rather than extras.

• Radon-in-water treatment, $1,200–$5,000. A second system entirely, treating the water supply rather than the air. It is only relevant on a private well — EPA notes a radon-in-water problem “is much more likely when its source is ground water, such as a private well” — and it rates aeration at 95 to 99 percent removal against 85 to 95 percent for granular activated carbon, while warning that GAC filters “can collect radioactivity and may require a special method of disposal”.
• Full crawl space encapsulation, $1,500–$15,000. A tenfold band, because it is a whole sealed-and-insulated envelope of which a radon membrane is one component. It is not a substitute figure for submembrane depressurisation. If radon is the only reason it is being proposed, submembrane suction is the targeted system and this line is not needed.

Tick both on a passive system and the calculator will happily show you a top end over $24,000, of which the radon air system is $2,500. That is not a bug — it is what a padded quote looks like when you itemise it, and making that legible is most of the point of this page.

What this calculator does not model

• No regional multiplier. Neither source read attaches a number to location, so none is applied. This is the same refusal, on the same grounds, that the foundation repair calculator documents.
• No saving for existing infrastructure. Drain tile, an existing sump pit and a stubbed-in passive pipe all make the job easier and EPA documents all three. Neither source prices the saving, so the calculator tells you what to ask for and adjusts nothing.
• No fan-replacement figure. HomeAdvisor puts fan replacement every 5 to 10 years and whole-system life at 10 to 30 years. EPA is more conservative — fans “may last five years or more”, with warranties that “tend not to exceed five years” — and explicitly declines to price the swap: “The cost to replace a fan varies as it is based on labor and materials.” So no figure is shown.
• No running cost inside the estimate. A mitigation fan draws 100–300 watts continuously and adds $30–$300 a year to the electricity bill. It is shown separately, because an installation estimate that quietly folds in an annual cost is neither.
• Nothing is scaled by your test result. EPA recommends fixing at 4 pCi/L or above and says you may want to consider fixing between 2 and 4, with outdoor air normally around 0.4 pCi/L. A reading of 20 and a reading of 4.1 are usually fixed by the same system, so the action level is context for whether to act and never an input to the price.

Related calculators

Radon is almost always found by a test ordered during a purchase, alongside three or four other findings. The home inspection cost calculator prices the radon test itself as one of its add-on tests, which is where this number usually starts, and the foundation repair cost calculator prices the other thing a suction-point crew often finds once it opens a slab.

If the house is on a private well, the well-water treatment line above is a second system — and the septic system cost calculator prices the other half of what a rural property asks for at closing. Where the reason the crawlspace is damp is drainage rather than radon, the sump pump & French drain cost calculator prices that — and note that an existing sump pit is often the cheapest place to put the radon suction pipe, so the two jobs are worth quoting together.

Methodology & sources

The cost figures on this page are generated from a single, sourced cost-data file (Installing a radon reduction system in an existing US home whose test came back at or above EPA's 4 pCi/L action level, priced by the type of system being quoted — active soil suction with a fan, or passive soil suction without one — rather than as one blended average. Diagnostic testing, the permit, the EPA-required post-mitigation retest, well-water treatment and crawl space encapsulation are priced as separate line items because they are separately engaged and separately invoiced. Suction-point count and slab area are carried as advisory context and multiply nothing, because neither source retrieved prices either. Cost bands are US national and reflect HomeAdvisor's page as updated 19 June 2026; the technical model, the effectiveness figures and the retest protocol are EPA's 2025 Consumer's Guide to Radon Reduction, which publishes no costs at all.). HomeAdvisor reports a member average of $1,028 on a normal range of $786–$1,274, with small homes as little as $395 and large or complex ones up to $2,453. Its system-type bands are wider and sit higher: active soil suction $1,000–$3,000, passive $500–$2,500. Those two cuts of the same page are in mild tension and both are shown, because the average is dominated by simple single-point jobs while the system band spans the whole market. EPA publishes no cost figures whatsoever in the 2025 edition of its Consumer's Guide — its technique table has an effectiveness column and no cost column, and the note beneath says only that mitigation costs are 'comparable to other common home repairs'. No per-suction-point cost and no per-square-foot rate is applied here, because neither exists in either source. Last verified September 2026.

• HomeAdvisor — How Much Does Radon Mitigation Cost? (page updated 19 Jun 2026) — retrieved 2026-09-11
• U.S. EPA — Consumer's Guide to Radon Reduction: How to Fix Your Home, EPA 402/K-10/005, 2025 edition (publishes no cost figures; supplies the action level, the per-technique effectiveness table, the retest protocol and fan service life) — retrieved 2026-09-11