How Much Does It Cost to Install an Under-Sink Water Filter? [2025 Data]

The average cost to install an under-sink water filter is $550, though you can spend between $100 and $3,000, depending on your needs. Under-sink water filters are more cost-effective than whole-house water filtration systems, and can provide similar water filtration results. However, they only serve a single faucet location. Learn the cost factors that will impact what you pay for an under-sink water filter.

Under-Sink Water Filter Cost Factors

The type and size of the under-sink water filtration system you choose will have the biggest impact on its price. However, several other factors will also figure into the calculation. 

Types

Many types of water filters exist. The most common under-sink varieties include carbon, multi-stage, reverse osmosis (RO), and systems that combine more than one type of filtration in the same unit. For example, many carbon filters come with a sediment filter as a first stage, while many RO systems include one or more stages of carbon filtration.

Reverse osmosis systems cost more to purchase and install than the other types, while ion exchange units act as point-of-use water softeners and cost less to install. UV light systems often involve other filtration methods before the UV purification happens, which can significantly increase their installation cost.  

Capacity

The amount of water you need per minute will affect the cost of your under-sink water filtration system. Water flow measurements are in gallons per minute or GPM. Common GPM rates for residential water filters are between 0.5 and 2.5. 

GPM rates can be somewhat deceptive. The higher the flow rate, the less filtration the water undergoes. Under-sink RO systems tend to have lower flow rates, but a high level of filtration. 

Included Supplies

Many under-sink water filters come with everything you need to tap into your home's plumbing and start enjoying filtered water. On the other hand, many systems come only as the filter housing. This means that in addition to the housing and connections, you'll have to purchase the faucet and sometimes the filters to complete your system, which will add to the installation costs. 

Labor

A plumber can install an under-sink water filter, as well as help you decide which system is best for your needs based on your family's consumption and the quality of your water. Plumbers cost between $45 and $200 per hour for installations and other work, which will affect the cost of installing your system. 

Prep

Understanding the current quality of your home's water is essential to help you choose the best under-sink water filtration system for your needs. Expect to spend between $10 and $400 on water testing, depending on whether you choose a DIY kit or have water samples sent to a lab for deeper analysis. 

Location

Where you live can impact the total installation cost for your under-sink water filter system. Expect to spend more to cover the cost of labor in locations where the cost of living is high and less in other areas. Additionally, because you're installing a plumbing fixture, some municipalities will require a plumbing permit for an under-sink system, which will include a minor fee. 

Under-Sink Water Filter Ongoing Costs

Installing an under-sink water filter isn't a one-and-done cost. There are a couple of things to consider regarding ongoing expenses. 

Maintenance 

Virtually all under-sink water filter systems require regular filter changes and upkeep to function properly. Under-sink water filter replacements cost between $15 and $300 each, and replacements are necessary every six months to five years, depending on the filter type and how often you use your system. 

Operating Costs 

Not all under-sink water filter systems require electricity. However, many RO systems and all UV light systems will require at least a small amount of it. While the cost is minimal, you may notice a small increase in your monthly electric bill. 

Why You Should Hire an Under-Sink Water Filter Installation Pro

Working with a pro is always a good idea when installing an under-sink water filtration system. While this job can be completed yourself, the relatively low cost and superior end results mean it’s always worth hiring a local water softener professional for help. These experts charge between $45 and $200 per hour, but the peace of mind that your filtration system is properly installed is more than worth the investment.

Here’s why it’s ideal to hire an under-sink water filtration pro

Working with a professional to install an under-sink water filter has many benefits, including:

• Ensuring code compliance

• Peace of mind from water leaks and other plumbing issues

• Help running electricity to the filter, if necessary

• Ensuring the filter is working correctly and protecting you from waterborne contaminants

• Complete the installation in a fraction of the time it would take to do by yourself

Cost of Common Under-Sink Water Filter Add-Ons

While you're hiring a professional for your under-sink water filter installation, it's a good time to knock off a few more items from your to-do list. 

• Water softener installation cost: $200–$6,000

• Plumbing inspection cost: $100–$500

• Plumbing repair cost: $175–$450

Tips to Reduce Cost While Installing an Under-Sink Water Filter

It's true that you can save money, at least in the short term, by installing your own under-sink water filter system. However, that's not the best option for every homeowner. Despite their smaller size compared to whole-house systems, they're still complex appliances that require precise installations, and working with plumbing and sometimes electrical isn't for everybody. 

The best way to manage costs when installing an under-sink water filter system is to test your home's water quality and what's in it, and work with a professional to find the most cost-effective way to treat the specific impurities that exist in your water. 

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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