How much does reverse osmosis cost, all in?

Advertised prices, verified

How to work out your true reverse osmosis cost

1. Price the system for your format. A countertop unit, an under-sink system with a tank, a tankless under-sink system and a whole-house setup sit at very different price points because they solve different problems. Decide where you want purified water first, then compare prices within that format using the table below rather than across formats.
2. Add installation, or plan the DIY afternoon. Most under-sink systems are designed for homeowner installation: a cold-line tee, a drain saddle and a faucet hole. If your countertop is stone or you want the line run to a refrigerator, a plumber visit gets added to the budget. Whole-house RO always needs professional design and installation, which is a real part of its cost.
3. Budget the recurring filter schedule. Every RO system has pre-filters and post-filters on a replacement schedule measured in months and a membrane measured in years. Before buying, look up what the replacement set costs from that vendor and how often it is due, because a cheap system with expensive cartridges can overtake a pricier system within a few years.

Why the quotes you see vary so much

Two systems that look identical under a sink can sit far apart in price because of what is inside: the number of filtration stages, whether a booster pump raises efficiency, whether the unit is tankless, and whether it adds remineralization or smart monitoring. None of those are gimmicks by definition, but each one you do not need is money spent on the wrong problem.

The other quiet variable is water waste. Reverse osmosis sends reject water down the drain as it purifies, and more efficient machines send less. If you are on metered municipal water or a low-yield well, a more efficient system pays some of its own premium back over its life. Our reverse osmosis water filter system cost page breaks down the equipment-side price drivers in more detail.

Where reverse osmosis is worth it, and where it is not

RO earns its cost when the problem is dissolved in the water: total dissolved solids, PFAS, nitrate, arsenic, lead at the tap. It is the wrong tool for hardness alone, where a softener protects the whole house for the same class of spend, and it is overkill if your only complaint is chlorine taste, which a good carbon filter fixes for far less.

Test before you buy. A proper water report tells you whether you need RO at one tap, treatment for the whole house, or both, and it turns the table below from a list of prices into a shortlist. Buying RO without a test means paying to fix a problem you have not confirmed you have.

Common questions

Is reverse osmosis expensive to run?

The running cost is the replacement schedule: pre-filters and post-filters on a months-based cycle and the membrane every few years. Vendors publish their cartridge prices, so you can total a full year of replacements before you commit to a system.

What is the median price for a reverse osmosis system?

The verified median across the vendors we track is $1,531. The table above shows each vendor's current published price so you can see where any given system sits against that midpoint.

Does reverse osmosis increase my water bill?

Slightly, because RO sends reject water to the drain while it purifies. Modern efficient systems, especially pumped tankless designs, waste far less than older ones, so efficiency is worth weighing if your water is metered.

Is professional installation required?

Not for most under-sink systems, which are built for DIY with basic tools. You will want a pro for stone countertop drilling, refrigerator lines, or any whole-house reverse osmosis project, which genuinely requires design work.

Browse by system type

• Compare Water softeners on advertised prices
• Compare Salt-free softeners on advertised prices
• Compare Whole-house filters on advertised prices
• Compare Reverse osmosis systems on advertised prices
• Compare Shower filters on advertised prices
• Compare Countertop filters on advertised prices
• Compare Refrigerator filters on advertised prices
• Compare Iron filters on advertised prices