64oz.org may earn commission for purchases made through the links posted on this page.

Water Softener Size: What Do I Actually Need for My House?

by Carl Jensen

Plumber, Welder, Contractor

> 2 min read

The timer and valve assembly of a water conditioner

When it comes to investing in a water softener for your home, there are multiple factors you should consider. From the amount of occupants living in your home to the water’s hardness level, these are just a couple of elements that can help you determine the capacity you need.

So, if you’re ready for better tasting, better feeling water, invest in a high-quality water softener to eliminate pipe-clogging minerals. With this simple guide, you’ll be able to make an informed decision about the best water softener size for your home and look forward to better quality water from your faucet.


several water softener filters for water stand in a row.water treatment system.ecology.

How Does a Water Softener Work?

Standard salt-based home water softeners, otherwise known as ion exchange units, are devices that solve lime-scale problems by removing harmful and unwanted minerals from the water before it reaches the faucets. 

These home units are connected to your plumbing system and are usually fitted close to the mains. This ensures all areas of your home benefit from water that has been softened. 

During the softening process, the ion exchange unit extracts magnesium, calcium, and other harmful minerals from your drinking water. These ions, which turn into limescale found in hard water, are replaced with harmless sodium ions.

The softener works by passing the hard water through a resin bead tank, which removes the magnesium and calcium ions. Once the resin beads cannot extract any more of these ions, they are refreshed by a process called regeneration.

A brine solution is flushed through the resin beads during the regeneration stage, removing any leftover limescale residue. This refreshes the beads and allows them to restart the water softening process.

Most Common Water Softener Sizes

A water softener’s ability depends on the hardness of the grains of water in one regeneration cycle. When it comes to deciding which capacity is best for you, you should also consider the softener’s salt efficiency. 

To give you an understanding of the different types, you’ll find a list of the most common home water softener sizes below. 

  • 0.7 ft3  of resin = 15,000 grains capacity
  • 1 ft3  of resin = 20,000 grains capacity
  • 1.5 ft3 of resin = 30,000 grains capacity

Other grain capacities that many sellers have on offer are 24,000, 32,000, and 64,000.

How to Calculate the Size You Need

To determine the water softener size you need, you’ll need to consider your water consumption and municipal water quality. These factors can help you choose the perfect size to maximize your soft water output, as well as minimizing your salt use. 

Start by calculating your daily water softening requirements: How much hard water do you need your softener to remove each day? Consider your water consumption and water hardness per day to calculate this. 

How to Calculate Your Water Consumption

  • To calculate your daily water consumption, the first step is to check your water bill.
  • This shows you how much water your household uses every month.
  • You can use this data to calculate how much water you use per day.
  • If you do not have access to this information, multiply the number of people in your household by 80 gallons (the average daily water consumption per person). For example, going by the calculation of 80x4, a family of 4 will use around 360 gallons of water every day. 

How to Calculate the Hardness of Your Water

Water hardness indicates how much magnesium and calcium are dissolved in your water. Although you can check the United States Geological Survey (USGS) water hardness map for an estimate of the mineral levels in your area or contact your local water utility for recent test results, there is also a simple test you can perform at home to assess your water quality, if you don’t have access to this information because your water comes from a well.

What You’ll Need

  • A water hardness test kit bottle with a water level line or a small glass bottle with a tight cap.
  • Dishwashing soap.
  • A measuring device marked in ml, cm3 or oz.


  • Fill the glass bottle or test kit bottle up to the line with water.
  • Add a drop of soap.
  • Shake and look for soap suds.
  • The more soap suds, the higher the hardness level.

What Size Water Softener Do You Require After Making These Calculations?

Once you’ve calculated your daily water consumption and water hardness, to figure out the perfect softener size for you, multiply your water consumption by hardness. This will equate to the water softening requirement you’ll need. 

For example, a family of four consumes 360 gallons per day. With water hardness of 10GPG (grams per gallon), this family’s daily softening requirement would be 360 gallons. This calculation is 10GPG (water hardness) x 360 gallons (daily consumption), equating to 3,600 grains of hardness every day. 

So, if your daily softening requirement is 3,600 grains, you will need a softener with a capacity of 25,000 grains. This is because 3,600 grains of hardness every day for 7 days equates to this capacity of water softener. 

How Much Does a Water Softener Cost?

Water softeners can range from $1,000-$3,000 for a full household system. Naturally, the more expensive the unit, the more efficient, reliant and durable it will be.

In regard to water softener pricing, it’s not just the amount of the unit you’ll need to consider. The capacity of the softener and the type of salt used can determine how little or expensive running costs are.

Enjoy Fresh and Purified Water With Your New Water Softener

If you’re ready to improve your water quality, investing in a water softener is a great option.

By extracting harmful minerals such as calcium and magnesium, you will see a whole host of benefits. From a better quality taste to healthier and softer skin, soft water can provide great improvements to your health. It is also kinder to your pipes and appliances too, as soft water reduces limescale formation. 

But to get the most out of your softener, you need the right size unit. Make the water softener calculations and invest in the perfect size water softener for your family. You can better enjoy water even more with great shower heads which can benefit you with improve your skin health.

Carl Jensen

About the Author

Carl Jensen is a plumber with over 50 years of experience in the industry, as well as related jobs like underwater welding. He runs a successful plumbing practice in Tampa, Florida, and contributes his plumbing expertise to our DIY articles, and helps to fact check and consult on most of our other stuff to boot.