Reverse Osmosis System Cost 2026: What You'll Actually Pay
A reverse osmosis system costs $300 to $950 installed under the sink and $4,800 to $8,000 for the whole house (HomeGuide), plus filters. Real prices, dated.
By Home Water Lab TeamUpdated Prices verified Oct 7, 2026
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A reverse osmosis system costs $300 to $950 installed under a kitchen sink and $4,800 to $8,000 for a whole house, per HomeGuide's 2026 cost guide (read Oct 12, 2026). The sticker is the smaller half of the bill. Over five years, cartridges and membranes cost as much as the unit or several times more, and that is where systems really differ. If you are still deciding whether you need a membrane at all, our buyer's guide to home reverse osmosis covers that first.
The short answer
as of Oct 12, 2026How much does a reverse osmosis system cost?
Under the sink, $300 to $700 installed with a tank and $450 to $950 tankless (HomeGuide); countertop units $200 to $450; whole-house systems $4,800 to $8,000 in HomeGuide's data but $1,000 to $4,800 in Angi's. Real prices on the makers' stores on Oct 12, 2026: $239.99 for the iSpring RCC7AK, $539 for the Waterdrop G3P600, $999 for the G3P800. Add $98 to $310 a year in filters, which is the number that decides five-year cost.
Key takeaways
- Under-sink RO: $300 to $950 installed (HomeGuide), $200 to $800 (Angi), both read Oct 12, 2026.
- Five years of filters on Oct 12, 2026 prices: $490.93 on an iSpring RCC7AK, $1,549.75 on an Aquasana SmartFlow.
- Under-sink labor runs $150 to $350 (HomeGuide); a new drain line adds $300 to $800 and an outlet $150 to $350.
- Whole-house RO: $4,800 to $8,000 installed per HomeGuide, $1,000 to $4,800 per Angi. The sources do not agree.
- Costco listed an iSpring 6-stage RO kit at $199.99 online on Oct 12, 2026, shown out of stock on its product page.
How Much Does a Reverse Osmosis System Cost?#
It depends first on where the system sits. Point-of-use units for one tap cost hundreds; whole-house systems cost thousands. The three national cost guides we read agree on that shape and disagree on the numbers, so here are all three, side by side.
| System type | HomeGuide, installed | Angi, average cost | Modernize |
|---|---|---|---|
| Countertop | $200 to $450 | $200 to $700 | $250 to $500 |
| Under sink, with tank | $300 to $700 | $200 to $800 | $200 to $600 |
| Under sink, tankless | $450 to $950 | $250 to $900 | $350 to $600 |
| Whole house | $4,800 to $8,000 | $1,000 to $4,800 | $1,000 to $6,000 |
HomeGuide's page is dated July 14, 2025 and titled for 2026; Angi's was updated July 10, 2026; Modernize shows no update date. All three were read Oct 12, 2026. Angi's headline average of $2,200 blends whole-house projects into the figure, which is why it looks high for a kitchen system. Dealer-installed brands sit apart: HomeGuide puts a Culligan under-sink RO at $1,050 to $1,700 installed, and our decode of the Culligan RO quote lines up every published figure for it.
What Do Real RO Systems Cost Today?#
Less than the guides suggest, if you install it yourself. On the makers' own stores on Oct 12, 2026, a certified tank system started at $239.99 and the tankless units we track ran $539 to $999.
Equipment prices on the makers' stores
as of Oct 12, 2026- iSpring RCC7AK, 6-stage tankiSpring store, $241.99 compare-at
- $239.99
- Aquasana SmartFlow, compact tank50% off banner; $449.99 MSRP
- $224.99
- Moen RO via SpringWell, 4-stageSpringWell store
- $363.80
- AquaTru Classic, countertopNo plumbing
- $475
- Waterdrop G3P600, tankless 600 GPDNeeds an outlet
- $539
- Waterdrop G3P800, tankless 800 GPDNeeds an outlet
- $999
Estimated 10-year total
$0
Prices read on each maker's store on Oct 12, 2026. Aquasana alternates between a sale banner and its MSRP, so both are shown; neither is a permanent price.
The Aquasana line is the one to watch. Its SmartFlow has sat at $199.99, $224.99 and $449.99 on different days since September, so compare it at both prices. The full ranking of these systems by use case is in our best reverse osmosis systems by budget.
iSpring
iSpring RCC7AK 6-Stage Reverse Osmosis System
Best for: A proven, cheap-to-run 6-stage under-sink RO with a very large owner base
- Stages
- 6 (with alkaline remineralization)
- Certification
- NSF/ANSI 58
- Waste ratio
- ~1:3 (classic tank design)
- Annual filter cost
- ~$100 to 110
What Does an RO System Cost to Own Over Five Years?#
Between about $730 and $1,800 for the under-sink systems we priced, filters included and installation left out. The spread comes almost entirely from the cartridges, not from the sticker.
5 years of ownership
as of Oct 12, 2026- Purchase priceThe price on the maker's own store on the reading date. Aquasana's is a banner price that comes and goes, so its list price is in the article too.
- Cartridges and membranes, 5 yearsEvery replacement the maker schedules over the period, at its own one-off prices, or its own published average annual cost where it prints one.
Our arithmetic on prices read on iSpring's, Aquasana's and Waterdrop's own stores on Oct 12, 2026. Waterdrop rows use Waterdrop's published average annual cost; iSpring and Aquasana rows count each replacement on the maker's schedule at its one-off price. Installation, water and electricity are excluded. A subscription discount or a different usage pattern moves every bar.
The SmartFlow's filters drive that gap. Aquasana schedules its carbon pair and remineralizer every six months and its membrane every 12, which came to $309.95 a year at one-off prices on Oct 12, 2026. At its $449.99 MSRP, five years total $1,999.74. A 15% subscription discount narrows the gap; it doesn't close it.
$730.92
The carbon row is there on purpose. A Claryum Direct Connect, which has no membrane at all, costs $1,044.89 over the same five years because its $91.99 cartridge goes every six months, as our Aquasana Claryum under-sink review details. Carbon is cheaper to buy, not always cheaper to keep.
How Much Does It Cost to Install a Reverse Osmosis System?#
Under the sink, $150 to $350 in labor per HomeGuide, or $100 to $300 for a point-of-use system per Angi (both read Oct 12, 2026). The extras are what turn a two-hour job into a bigger bill.
Installation, line by line
as of Oct 12, 2026- Under-sink laborHomeGuide; Angi says $100 to $300 for point-of-use
- $150 to $350
- Plumber, hourlyHomeGuide; Angi says $45 to $200
- $45 to $150 / hr
- New drain lineHomeGuide, only if there is no drain to tap
- $300 to $800
- New outlet under the sinkHomeGuide, tankless units only
- $150 to $350
- Booster pumpAngi, for low incoming pressure
- $50 to $300
- Whole-house laborHomeGuide; Angi says closer to $1,500
- $300 to $500
Estimated 10-year total
$0
HomeGuide's reverse osmosis cost guide and Angi's RO cost guide, both read Oct 12, 2026. Ranges are national and exclude the system itself.
Five things that decide your install bill
5 itemsiSpring sells the RCC7AK as a DIY kit with every part in the box, and the faucet hole is usually the step that sends people to a plumber. Tank against tankless for your cabinet is covered in our comparison of under-sink RO systems, and the outlet question in detail in our tankless RO rankings with power needs.
How Much Does a Whole House Reverse Osmosis System Cost?#
Between $1,000 and $8,000 installed depending on which guide you read, and up to $16,695 for equipment alone on one maker's store. HomeGuide prices it at $4,800 to $8,000 installed by capacity, from $4,800 to $7,000 at 500 gallons a day to $5,800 to $8,000 at 1,500. Angi says $1,000 to $4,800, Modernize $1,000 to $6,000.
The maker prices we read on Oct 12, 2026 show why the guides diverge. Crystal Quest's whole-house RO starts at $2,227 for 300 GPD with no storage tank and runs to $10,088 configured. US Water Systems' Defender starts at $9,695 at 4,000 GPD and reaches $16,695. Neither price includes the tank, pump, pretreatment or installation a working system may need.
Most homes do not need one. Our guide to when a whole-house membrane makes sense runs the short list of cases that justify it. Very hard water also needs pretreatment ahead of the membrane, and HomeGuide puts a softener at $1,200 to $3,800 installed, so read up on how a home water softener works before pricing the pair.
How Much Does Costco Reverse Osmosis Cost?#
Costco listed an iSpring 6-stage alkaline RO system with faucet at $199.99 on its filters page on Oct 12, 2026. The product page names it model RCC7AKF3, Costco item 2997787, a kit that includes one extra set of stage 1 to 3 filters, and showed it out of stock without a warehouse selected.
Two other RO systems carried online prices that day: the Pure Blue 1:1 at $189.99 and the Brondell Circle at $369.99, both shown out of stock. A Pure Blue one-year filter pack was $39.99 and its membrane $57.99. Warehouse prices and stock vary by location, and Costco's installed water program runs through EcoWater dealers with no published prices, as our guide to what Costco sells for water treatment explains.
How Much Do Reverse Osmosis Filters Cost a Year?#
About $98 to $310 a year on the systems we priced on Oct 12, 2026. Generic guides give lower per-filter figures: HomeGuide says $20 to $100 per point-of-use filter, Angi says $40 to $90 a set plus $30 to $100 per membrane every two to five years.
| System | Yearly filter cost, Oct 12, 2026 | What it covers |
|---|---|---|
| iSpring RCC7AK | $98.19 | F9K set at $80.99, plus an MC7 membrane at $42.99 every 2.5 years, averaged |
| Waterdrop G3P600 | $144.97 | Waterdrop's published average annual cost |
| Waterdrop G3P800 | $159.97 | Waterdrop's published average annual cost |
| Aquasana SmartFlow | $309.95 | Two carbon sets, one membrane, two remineralizers at one-off prices |
Water is the other running cost. EPA's WaterSense page, updated Aug 21, 2026, puts a typical point-of-use RO system at five gallons or more to the drain per gallon treated, against 2.3 or less for a WaterSense-labeled one. HomeGuide prices the resulting RO water at $0.03 to $0.10 a gallon. Our teardown of the G3P800's drain ratio and price shows what a published 3:1 pure-to-drain ratio changes.
Is a Reverse Osmosis System Worth the Cost?#
Yes, when a water test shows something only a membrane removes: fluoride, nitrate, arsenic or high total dissolved solids. For chlorine and taste on city water, a carbon filter does the job for less up front, though not always for less over five years.
Pay for RO
- Your utility report or well test shows nitrate, fluoride or arsenic
- High TDS makes the water taste salty or metallic
- You want one certified drinking tap rather than bottled water
- You can live with a drain line and a slower faucet
Skip RO
- The complaint is chlorine taste or smell on city water
- The problem is scale and hardness at every tap
- You rent and cannot drill or plumb
- You will not keep up with six-month cartridges
The call
Test first, then buy the cheapest certified system that removes what the test found, priced over five years.
If drilling is the deal-breaker, our countertop filters that need no plumbing include the AquaTru Classic at $475, certified to NSF/ANSI 58, and what its filters really cost a year once the gallon limits on its data sheet are counted is worked out in our AquaTru review. On a private well, test before you shop, as our private well water treatment guide explains, and if you are unsure which system fits your house, our two-minute system quiz narrows it down.
AquaTru
AquaTru Classic Countertop Reverse Osmosis Purifier
Best for: Renters and anyone who wants named, third-party RO certification without touching a pipe
- Install
- None, 120V plug and a countertop
- Stages
- 4 (pre/carbon, RO membrane, VOC carbon)
- Clean tank
- 0.75 gallon
- Certification
- Tested and certified by IAPMO to NSF 42, 53, 58 and 401 (data sheet adds 372)
- Filter life
- 6 months or 600 gal (pre/carbon), 24 months or 1,200 gal (RO), whichever comes first
- Replacement filters
- $59.95 RO, $39.95 VOC carbon, $49.95 Mineral Boost
HomeGuide's guide is dated July 14, 2025, Angi's was updated July 10, 2026 and Modernize's shows no date; all were read Oct 12, 2026, as were every maker price and the Costco listings. Where the guides disagree, all three are shown. Five-year totals and yearly filter costs are our arithmetic on the makers' published prices and schedules. We did not install or test these systems for this page.
RO cost questions people ask
How much does a reverse osmosis system cost per month?
On Oct 12, 2026 prices, filters alone come to about $8 a month on an iSpring RCC7AK, $12 to $13 on the Waterdrop G3P600 and G3P800, and $26 on an Aquasana SmartFlow at one-off prices. Spread the purchase over five years and the RCC7AK totals about $12 a month all in.
How much does a Culligan reverse osmosis system cost?
HomeGuide puts a Culligan under-sink RO at $1,050 to $1,700 installed and rental at $10 to $30 a month including maintenance (read Oct 12, 2026). Culligan sells through local dealers and publishes no national prices.
Why do reverse osmosis cost estimates vary so much?
Because the guides mix different things. Some quote equipment only, some quote installed totals, and Angi's $2,200 average blends whole-house projects into its number. Compare like with like: one tap or the whole house, installed or not, and five years of filters.
Does a reverse osmosis system raise the water bill?
A little. EPA says a typical point-of-use RO sends five gallons or more to the drain per gallon treated, and HomeGuide prices RO water at $0.03 to $0.10 a gallon depending on local rates. Tankless designs with published ratios such as 2:1 or 3:1 waste less.
Frequently asked questions
How much does a reverse osmosis system cost?
An under-sink system costs $300 to $950 installed in HomeGuide's guide, $200 to $800 in Angi's, and a countertop unit $200 to $450 (HomeGuide). On the makers' own stores on Oct 12, 2026, the iSpring RCC7AK was $239.99, the Waterdrop G3P600 $539 and the G3P800 $999. Filters add about $98 to $310 a year depending on the system.
How much does it cost to install a reverse osmosis system?
Labor for an under-sink system runs $150 to $350 in HomeGuide's 2026 guide, and Angi puts a point-of-use install at $100 to $300. Extras can add more: $300 to $800 for a new drain line and $150 to $350 for an outlet under the sink for a tankless unit, both HomeGuide figures. Many tank systems ship as DIY kits: iSpring says every part the RCC7AK needs is in the box.
How much does a whole house reverse osmosis system cost?
Published ranges disagree. HomeGuide puts a whole-house system at $4,800 to $8,000 installed, Angi at $1,000 to $4,800 and Modernize at $1,000 to $6,000 (all read Oct 12, 2026). Equipment on the makers' stores that day ran from $2,227 for a 300 GPD Crystal Quest unit with no storage tank to $16,695 for a configured US Water Systems Defender.
Is reverse osmosis worth the cost?
When a water test shows dissolved contaminants such as fluoride, nitrate, arsenic or high TDS, yes, because carbon filters do not remove them. For chlorine and taste alone, a carbon filter does the job for less. Budget on five years, not the sticker: an iSpring RCC7AK came to $730.92 over five years at Oct 12, 2026 prices, filters included.
How much do reverse osmosis filters cost?
HomeGuide puts point-of-use RO filters at $20 to $100 each, and Angi a set at $40 to $90, plus $30 to $100 for a membrane every two to five years. Real yearly totals on Oct 12, 2026: about $98 for an iSpring RCC7AK, $144.97 and $159.97 for the Waterdrop G3P600 and G3P800 (Waterdrop's figures), and $309.95 for the Aquasana SmartFlow at one-off prices.
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