What Size Water Softener does My Family Need

What Size Water Softener does My Family Need? How to Decide?

Want to purchase a water softener for your family but don’t know what size will be perfect for your family?

Worry not, I have brought in this article all the factors that will help you decide and buy the ideal-sized water softener. 

Let’s jump in!

Understanding your city’s water softener hardness level?

Identifying your water’s hardness is the first step. Water supplies may contain varying amounts of minerals depending on where you live. Marble, limestone, and chalk are the most common sources of calcium carbonate.

4% of the earth’s crust is calcium carbonate, formed over millions of years through the sedimentation of shells and coral. Despite this, soil and water do not contain the same minerals.

There is also the possibility that magnesium, copper, iron, and zinc are present in your supply.

If you want to know how hard your water is, you can buy a water-testing kit, order a quality report from your water provider, or take a water sample to an independent lab.

A clear water bottle and soap can be used to perform a DIY test at home, revealing the hardness level of your home water. Your water’s hardness will be determined by how many bubbles form after you mix soap and water in the bottle: the fewer bubbles, the harder your water is.

The result is expressed in milligrams per liter (mgL) or grains per gallon (gpg). 

Below is a table that shows both measurements. 

mgL contents gpg contents 
Soft water level –    0-60    0-03
Slightly hard water level –    61-120    03-07
Hard water level –    121-180     07-11
Very hard/undrinkable water level –     180+     11+

By knowing your water’s hardness value, you’ll be able to determine whether your water is hard, soft, or somewhere in between. Having this value on hand will be necessary when we get to the water softener calculator.

Your city’s water supply can also be investigated if you receive municipal water. If you live in Minneapolis, Las Vegas, or Los Angeles, there’s a high chance that you would benefit from a water softener. These metro areas have some of the country’s hardest water.

How much water do you use?

Choosing the right water-softening system begins with knowing how much water your household uses each month. You should see a graph of your historical water usage on your bill. Your household’s daily water consumption can be estimated from the information above.

Your water-softening requirements can be calculated using the formula below. 

Your household’s average daily water consumption can be calculated using the number of people multiplied by 75. Go by this method if you don’t have a water bill or are on well water.

For example, the average family of three needs 225 gallons of soft water per day, or roughly three (no. of people) x 75 gallons (per person).

Your average daily water usage should be known when you decide what size water softener to buy.

It includes all the water you use, not just your drinking water.

You should also consider how much water you consume in your household based on the number of people. You should also consider the number of appliances in your home and the frequency at which they are used.

The more water you use per day – and the more water-based appliances you use – the bigger capacity water softener you’ll need.

The smaller capacity of a water softener will be sufficient if you use less water daily.

Finding how many Grains to be Removed? 

Once you have determined what size water softener to buy, the next step is determining how many grains should be removed. There are 65 milligrams of calcium carbonate in one grain, which is the unit of measurement for calcium carbonate. 

As calcium is the mineral that causes hardness in water, water softeners are rated based on how much calcium they can remove.

Depending on grain capacity, water softener systems range from 24,000 GPG (grains per gallon) to 64,000 GPG. Less grain will be removed if the number is smaller.

After you have tested your water and know how many grains per gallon are in your supply, multiply that number by your household’s daily consumption. According to the above example, a household of three using 225 gallons of water per day would need a water softener to remove 2,250 grains of hardness each day.

You must multiply 2,250 by 7 to get the correct size water softener since water softeners regenerate once every seven days. Considering this, a 15750 gpg water softener would be needed as per the example considered. (For a family of 3 people)

REMEMBER – Here is a formula that will help you determine what water softener is right for you: Water Softener Capacity Requirement = Average Daily Water Consumption x Water Hardness (grains per gallon) x 7

What size Water Softener is Right for Family of 4?

The most suitable water softener for families with four members is a 32,000 or 33,000-grain water softener. 

Is that number too high, considering the formula above? 

You’re right! It is higher. That is because when you purchase a water softener, you also need to consider salt consumption. 

A family of 4 may be able to use a 24,000-grain softener, but the amount of salt required will be much more. With a 32,000 softener, you won’t have to add as much salt as you would with the other unit, saving you money over time. 

What size Water Softener is Right for Family of 5?

An average family of five would be expected to use 375 gallons of water per day using 75 gallons per day multiplied by five. In this case, a family of 5 with 10 gpg of hardness would need to remove 26,250 gpg per week. 

Last but not least, a 40,000-grain water softener would be suitable for a family of five. This is based on salt usage and overall optimization of the whole experience of using a water softener in the long run.

What size Water Softener is Right for Family of 6?

Water softeners rated at 48,000 grains are suitable for families of 6 people with low-to-medium hardness levels.

(this has been estimated based on the formula used for calculation mentioned up to now.)

Having 48,000 grains rated water softener will ensure maximum soft water and satisfaction for a family of 6 people.  

What size Water Softener is Right for Family of 3?

The average grain capacity of a softener for households with three people or fewer is around 20,000 units. 

I have already calculated (15750 gpg) and written the size of the water softener a family of three would be satisfied with.


What size water softener to get for your family? (May it be a family of 3 or 4 or 5 or even people and more.)

Test your water to know how many grains would need to be eliminated.

After this, calculate your household’s water usage using the formula mentioned.

And voila! You are ready to decide the size of the water softener needed for you and your family.