Reverse Osmosis Cost: Systems, Install, and Upkeep

By Filtiva Editorial Team · Updated Nov 9, 2026 · 12 min read

Filtiva is reader-supported. We may earn a commission from links on this page. Learn more

Illustration of an open under-sink cabinet with three RO filter housings, a membrane, and a storage tank, beside a stack of coins and a checklist
On this page

Quick answer

**An under sink reverse osmosis system typically costs about $300 to $950 installed, and a whole-house system costs far more.** HomeGuide puts a tank model at $300 to $700 and a tankless model at $450 to $950, both installed. Whole-house RO is where sources disagree: HomeGuide says $4,800 to $8,000, while Angi says $1,000 to $4,800. Budget about $50 to $250 a year for filters and membranes after that (HomeGuide).

"How much does reverse osmosis cost?" has two honest answers. The system itself is the smaller part for most homes. The rest is installation, filters, a membrane that needs replacing, and the water the system sends down the drain.

This guide pulls national cost data from HomeGuide, Angi, and This Old House, adds EPA figures for upkeep and waste water, and shows what the numbers add up to over five years. It also explains why the published ranges for whole-house systems are so far apart, and where you can save money without cutting corners.

Before you start: These are national estimates, not quotes. Prices vary with your plumbing, your water, and your local labor rates. Get at least two written quotes for any whole-house job, and test your water first so you buy only the treatment you need.

How much does a reverse osmosis system cost?

Two things set the price: how much water the system treats, and who installs it. A point-of-use (POU) system treats one faucet, usually the kitchen sink. A whole-house system treats everything that enters your home.

Range bars of reverse osmosis cost by type: HomeGuide installed $300–$950 under sink and $4,800–$8,000 whole-house, Angi $1,000–$4,800 whole-house
System type HomeGuide (installed) Angi (average cost)
Countertop RO $200–$450 $200–$700
Under sink, with tank $300–$700 $200–$800 (under sink)
Under sink, tankless $450–$950 $250–$900
Whole-house RO $4,800–$8,000 $1,000–$4,800

Sources: HomeGuide (dated July 2025) and Angi (updated Sep 24, 2026). Angi lists a single under sink range, so it is shown next to HomeGuide's tank row.

For a typical home that wants better drinking and cooking water, the under sink row is the one that matters. HomeGuide says tankless models have higher capacities that suit homes of four or more people. Our under sink reverse osmosis system guide explains tank versus tankless in detail, including what "gallons per day" does and doesn't tell you.

Why the whole-house numbers don't agree

HomeGuide's $4,800 to $8,000 describes a whole-house RO system with a 150- to 500-gallon storage tank, a pump, and the RO unit, installed on the main line. Angi and This Old House both put whole-house RO at $1,000 to $4,800, and This Old House says some packages with a water softener reach about $10,000 (This Old House, updated Mar 30, 2026).

Dealers can quote higher still. One Central Pennsylvania dealer's published guide, dated March 5, 2026, says a whole-house system there ranges from $8,000 to $20,000 or more installed, with pre-treatment often required (HQ Water Solutions). That is one local dealer, not a national figure. But it shows why a quote for the same house can land far from an online average.

The takeaway: treat any whole-house number as a starting range, and ask each installer what is in it. Is it a pump? A storage tank? Pre-filters or a softener? A drain line?

How much does it cost to install a reverse osmosis system?

HomeGuide puts installation labor at $150 to $500, depending on system type and complexity. For an under sink system, it breaks that down this way (HomeGuide):

Cost item Under sink Whole-house
System and materials $150–$600 $4,500–$7,500
Labor to install $150–$350 $300–$500
Total installed $300–$950 $4,800–$8,000

Other sources put professional labor a bit higher. Angi says installation averages $300 to $700, with POU systems typically $100 to $300 and whole-house systems close to $1,500 in labor alone (Angi). This Old House puts a typical POU install at $150 to $300, with complex jobs reaching $1,500.

Extras that raise the bill

HomeGuide lists several add-ons that can push the quote up:

  • A drain connection. Every RO system needs one to carry away waste water. A new drain pipe costs $300 to $800 installed.
  • Electrical access. A new outlet runs $150 to $350 for systems that need power, such as whole-house units.
  • Countertop work. Cutting a hole for a separate RO faucet raises labor.
  • Pre-treatment. For very hard water, HomeGuide says a water softener ahead of the RO costs $1,200 to $3,800 installed. See our water softener cost guide for that side of the budget.
  • Water testing. HomeGuide lists DIY kits at $10 to $30 and lab testing at $100 to $300.

Angi adds typical add-on prices of $50 to $300 for a booster pump (for low pressure), $200 to $500 for UV filtration, and $150 to $300 for an alkaline remineralization kit.

A DIY install can cut labor. This Old House estimates DIY savings of $100 to $300 on small units, but warns that plumbing mistakes can cause expensive water damage. Whole-house systems are a job for a licensed pro.

What does a reverse osmosis system cost to run?

Running costs come from three places: filters, the membrane, and water.

Filters and membranes

The EPA says most RO systems need pre-filter replacement about every six months and a new membrane every one to five years, depending on local water quality and use. Follow the manufacturer's schedule (EPA WaterSense).

Upkeep item How often Typical cost
Replacement filter cartridges (POU) Every 6 months to 1 year (HomeGuide) $20–$100 (HomeGuide); a standard set $40–$90 (Angi)
RO membrane Every 2–5 years (HomeGuide, Angi); EPA says 1–5 years $30–$100 (Angi)
Whole-house RO filters Every 3–6 months or so (Angi) $150–$250 each (HomeGuide)
Overall upkeep, under sink Yearly $50–$250 a year (HomeGuide)

Large systems or ones that need specialty filters can cost more. Angi says to budget $100 to $300 a year in those cases. The more stages a system has, the more cartridges you replace, so ask how many it uses before you buy. For the full replacement calendar, see our water filtration maintenance guide.

Waste water

RO systems send water down the drain. The EPA says a typical system sends five gallons or more of reject water down the drain for every gallon of treated water. A WaterSense labeled RO system sends no more than 2.3 gallons (EPA WaterSense).

The EPA also says choosing a WaterSense labeled system over a typical one can cut a household's water use by more than 3,100 gallons a year and save nearly $50 a year in water and wastewater costs. HomeGuide puts the water cost of RO output at $0.03 to $0.10 per gallon, depending on local tap water rates.

Angi says newer high-efficiency systems can reach a one-to-one waste ratio but cost about $300 more up front. Here's the simple math: $300 more, divided by about $50 a year in savings, is roughly six years to break even on water savings alone. That's Filtiva math, and it mixes two sources and two efficiency levels, so treat it as a rough guide. Your local water and sewer rates will change the answer.

What will an under sink system cost over five years?

Adding the installed price to five years of upkeep gives a better picture than the sticker price alone. We combined HomeGuide's installed ranges with its $50 to $250 yearly upkeep range:

Stacked bar chart of five-year cost: tank system $550 to $1,950, tankless system $700 to $2,200, from installed price plus upkeep
System Installed price 5 years of upkeep 5-year total
Under sink, tank $300–$700 $250–$1,250 $550–$1,950
Under sink, tankless $450–$950 $250–$1,250 $700–$2,200

Filtiva math from HomeGuide ranges. Excludes your water and sewer bill and any pre-treatment.

The spread is wide because the low end assumes a simple install and cheap filters, and the high end assumes a complex install and costly filters. EPA says a well-maintained RO system can last 15 years, so the per-year cost keeps falling the longer you keep it running, as long as you keep up with filter changes.

Is whole-house reverse osmosis worth it?

For most homes, probably not. The EPA says point-of-use RO systems are designed to treat water for drinking and cooking. Using RO for clothes washing, toilet flushing, or bathing, which don't need that quality, can waste more water (EPA WaterSense).

A whole-house RO system makes more sense in narrower cases, for example a private well with several water problems at once. This Old House notes that point-of-entry RO is best for homes with hard water or high chlorine, or those using well water or rainwater. If that sounds like your home, test first. Our well water filtration systems guide explains how to read a lab report and match treatment to it. If you are comparing whole-house options that aren't RO, see our whole house water filtration system cost guide.

Buy, rent, or hire a service?

HomeGuide says renting a Culligan RO system costs $10 to $30 a month, including maintenance, and puts a purchased Culligan under sink system at $1,050 to $1,700 installed. Renting spreads out the cost and bundles upkeep, but you don't own the equipment. At the rental range, five years of payments come to $600 to $1,800. That's Filtiva math on HomeGuide's range, and it excludes any contract terms, fees, or price changes, so read the agreement.

If you own a system but don't want to change filters yourself, a service plan can cover it. Our water filtration service guide covers what plans include and what dealers charge.

How to get a fair RO quote

  1. Test your water first. Hard water can call for a softener ahead of the RO. Our guide to testing water hardness explains the options.
  2. Ask what the number includes. Install, drain connection, faucet, tank, pump, pre-filters, and permits.
  3. Get the filter and membrane schedule in writing. Ask what each replacement costs and how many cartridges the system has.
  4. Ask about waste water. Is the system WaterSense labeled? What is its drain-to-product ratio?
  5. Check certifications for the exact model. Our under sink guide explains NSF/ANSI 58 and how to look up a model.
  6. Compare at least two quotes. HomeGuide advises against automatically accepting low quotes, which may signal low-quality work.
  7. Ask who handles warranty and service. Get the labor warranty in writing.

Ways to keep the cost down

Pros

  • Doing a simple under sink install yourself can save labor, if you are comfortable with plumbing
  • A WaterSense labeled model can cut waste water and the water bill
  • Fewer stages or longer-life filters can lower yearly upkeep
  • Testing first avoids paying for treatment you don't need

Cons

  • A DIY mistake can cause water damage that costs more than the labor saved
  • Higher-efficiency models cost more up front
  • The cheapest unit may have costlier, harder-to-find filters
  • Whole-house RO has a high price and high water use compared with point-of-use

Other ways to save, from Angi: buy a refurbished unit only if it comes with a warranty, compare brands, and request multiple installation quotes.

The bottom line

For most homes, reverse osmosis costs about $300 to $950 installed under the sink, plus roughly $50 to $250 a year to keep running. Over five years, that works out to about $550 to $2,200 using HomeGuide's ranges. Whole-house RO is a much bigger purchase, and published prices range from $1,000 to $8,000 or more, so get itemized quotes.

Test your water, pick the smallest system that solves your problem, and check the certification for the exact model. For maintenance tasks, see our water filtration repair guide, and browse all reverse osmosis guides. Learn how we research our guides.

FAQ

Frequently asked questions

How much does a reverse osmosis system cost?
HomeGuide puts an under sink RO system at $300 to $950 installed, with tank models at $300 to $700 and tankless at $450 to $950. A whole-house system is $4,800 to $8,000 installed by HomeGuide's numbers, but Angi puts whole-house RO at $1,000 to $4,800. Treat these as national estimates, not quotes.
How much does it cost to install a reverse osmosis system?
HomeGuide lists installation labor at $150 to $350 for an under sink system and $300 to $500 for a whole-house system. Angi says professional installation averages $300 to $700. A drain connection, new outlet, or countertop work can add to the bill, and DIY installation of a small unit can save labor.
How much does reverse osmosis cost to run each year?
HomeGuide estimates $50 to $250 a year in upkeep, depending on the filter types. The EPA says most systems need pre-filter replacement about every six months and a new membrane every one to five years, so follow the maker's schedule. Water used for waste is extra and depends on your local rates.
Does reverse osmosis raise your water bill?
It can. The EPA says a typical RO system sends five gallons or more down the drain for every gallon it treats, while a WaterSense labeled model sends no more than 2.3 gallons. The EPA estimates the WaterSense label saves a household more than 3,100 gallons and nearly $50 a year compared with a typical system.
Is whole-house reverse osmosis worth it?
For most homes, point-of-use RO at the kitchen sink is enough, because the EPA says these systems are designed for drinking and cooking water. Whole-house RO costs much more and is mainly worth considering for private wells or water with several problems. Get a lab test first and compare itemized quotes.
How long does a reverse osmosis system last?
The EPA says a well-maintained RO system can last 15 years. Parts wear sooner: HomeGuide says filters need changing every 6 months to 1 year and membranes every 2 to 5 years, while the EPA gives a 1 to 5 year range for membranes depending on local water and use.
Is it cheaper to rent a reverse osmosis system?
HomeGuide says renting a Culligan RO system costs $10 to $30 a month with maintenance included, compared with $1,050 to $1,700 installed to buy one. Over five years, the rental range totals $600 to $1,800 by our math. Check contract terms, fees, and what happens when you stop renting.

Sources

Cost figures are national estimates from the publishers above as of their latest updates and are not quotes. Filtiva does not sell or install reverse osmosis systems and has not hands-on tested the products mentioned. Always follow the manufacturer's installation and maintenance instructions.

Filtiva earns commissions from some links on this page at no extra cost to you. Commissions never change our criteria. We have not hands-on tested the products mentioned; all facts come from the linked sources, checked on November 9, 2026.

Keep reading

Under Sink Reverse Osmosis: Costs, Stages & Buying Guide