How Much Does It Cost to Install an Under-Sink Water Filter? [2026 Data]

In 2026, the national average cost to install an under-sink water filter is $550. Most homeowners spend between $300 and $1,250, with total costs driven by filter type, system complexity, and installation labor. Under-sink water filters are more cost-effective than whole-house water filtration systems and can deliver similar water filtration results, though they serve only a single faucet location.

Under-Sink Water Filter Cost Factors: What Determines the Price?

The type and size of the under-sink water filtration system you choose have the biggest impact on its price. Several other factors — including labor, location, and included supplies — also figure into the final calculation.

Types

There are many types of water filters available, with the most common under-sink varieties being carbon, multi-stage, reverse osmosis (RO), and combination systems that use more than one filtration method in a single unit. Ion exchange units act as point-of-use water softeners and tend to cost less to install, while reverse osmosis systems cost more to purchase and install than other types. UV light systems often incorporate additional filtration stages before the UV purification step, which can significantly increase their installation cost. The following table breaks down average cost ranges by filter type:

Capacity

The amount of water your household needs per minute directly affects the cost of your under-sink water filtration system, with common residential GPM rates ranging from 0.5 to 2.5. Higher flow rates can be misleading — the faster the water moves through the filter, the less filtration it actually receives. Under-sink RO systems typically operate at lower flow rates but deliver higher filtration performance. The table below shows average minimum costs by flow rate:

Included Supplies

Many under-sink water filters come with everything you need to connect to your home's plumbing and start using filtered water right away. Others are sold as filter housing only, which means you'll need to separately purchase the faucet and sometimes the filters themselves to complete the system. These additional purchases will add to your overall installation costs, so confirm what's included before buying a unit.

Labor

A plumber can install an under-sink water filter and help you determine which system best fits your household's consumption and water quality needs. Plumbers cost between $45 and $200 per hour for installations and other work, and this labor rate will have a direct impact on your total installation cost.

Prep

Understanding your home's current water quality is essential to choosing the right under-sink water filtration system. Water testing costs between $10 and $400, depending on whether you use a DIY kit or send samples to a lab for deeper analysis. Lab testing costs more but provides a more complete picture of the contaminants in your water, helping you select the most effective filter type.

Location

Where you live can meaningfully impact the total installation cost for your under-sink water filter system. Labor costs are higher in areas with a higher cost of living and lower in other regions. Some municipalities also require a plumbing permit when installing a plumbing fixture like an under-sink filter, which will add a minor fee to your project total.

Under-Sink Water Filter Ongoing Costs: What to Budget For

Installing an under-sink water filter comes with ongoing costs beyond the initial installation. Budgeting for regular maintenance and, in some cases, electricity will help you avoid surprises over the life of your system.

Maintenance

Virtually all under-sink water filter systems require regular filter changes and upkeep to function properly, making maintenance an unavoidable ongoing expense. Replacement filters cost between $15 and $300 each, depending on the filter type and system. How often you replace them depends on usage and filter type, with intervals ranging from every six months to every five years.

Operating Costs

Not all under-sink water filter systems require electricity to operate. Many RO systems and all UV light systems do draw at least a small amount of power, which may result in a modest increase in your monthly electric bill. The cost is generally minimal, but it's worth factoring in when comparing system types.

How Much Does It Cost to Hire an Under-Sink Water Filter Pro?

Hiring a pro to install your under-sink water filtration system is almost always worth it, even though this is a job some homeowners attempt themselves. These experts charge between $45 and $200 per hour, and hiring a local water softener professional ensures your system is properly installed and functioning correctly. The peace of mind that comes with a professional installation — including proper connections and code compliance — makes the investment well worth it.

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

Under-Sink Water Filter Additional Costs: What Should You Consider?

While a pro is already on-site for your under-sink water filter installation, it's a smart time to bundle other related home projects. Here are some common add-on services to consider:

• 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. 

Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.