Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Installed cost
$1,500
Recommended grain capacity
14,400
Grains removed per day
3,600
Regenerations per year
91
Annual salt cost
$164
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter people in household.
- 2Enter water hardness (grains/gal).
- 3Enter water use per person (gal/day).
- 4Enter target days between regenerations.
- 5Enter softener unit price ($).
- 6Enter plumbing + install labor ($).
- 7Enter salt price per 40-lb bag ($).
- 8Read your installed cost on the right — it updates as you type.
- 9Hit Share to keep the scenario or send it to someone.
About this calculator
Sizing a water softener starts with grains per gallon of hardness and how much water your household actually uses — roughly 75 gallons per person per day. Multiply the two and you get daily grain removal; a properly sized softener regenerates every three to five days, so most families land on a 32,000 or 48,000 grain unit. Undersizing means constant regeneration and salt waste; oversizing wastes money up front and can leave resin sitting too long between cycles. This calculator sizes the unit, prices installation with or without new plumbing and a drain line, and projects annual salt cost. 2026 US national averages run about $1,200-$2,800 installed for a standard whole-house ion-exchange system.
Worked example
Using the values the calculator loads with:
Inputs
- People in household: 4
- Water hardness: 12 grains/gal
- Water use per person: 75 gal/day
- Target days between regenerations: 4
- Softener unit price: 900 $
- Plumbing + install labor: 600 $
- Salt price per 40-lb bag: 9 $
Results
- Installed cost: $1,500
- Recommended grain capacity: 14,400
- Grains removed per day: 3,600
- Regenerations per year: 91
- Annual salt cost: $164
What each field means
Inputs
- People in household
- The people in household used in the calculation. Starts at 4 so you have a working example on load. Accepted range: 1–12.
- Water hardness (grains/gal)
- The water hardness used in the calculation, measured in grains/gal. Starts at 12 grains/gal so you have a working example on load. Accepted range: 1–60 grains/gal.
- Water use per person (gal/day)
- The water use per person used in the calculation, measured in gal/day. Starts at 75 gal/day so you have a working example on load. Accepted range: 30–150 gal/day.
- Target days between regenerations
- The target days between regenerations used in the calculation. Starts at 4 so you have a working example on load. Accepted range: 2–10.
- Softener unit price ($)
- The softener unit price used in the calculation, measured in $. Starts at 900 $ so you have a working example on load. Accepted range: 300–4000 $.
- Plumbing + install labor ($)
- The plumbing + install labor used in the calculation, measured in $. Starts at 600 $ so you have a working example on load. Accepted range: 0–3000 $.
- Salt price per 40-lb bag ($)
- The salt price per 40-lb bag used in the calculation, measured in $. Starts at 9 $ so you have a working example on load. Accepted range: 3–25 $.
Results
- Installed cost
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Recommended grain capacity
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Grains removed per day
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Regenerations per year
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Annual salt cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How do I find my water hardness?
Municipal utilities publish it in the annual water quality report, usually in grains per gallon or parts per million (divide ppm by 17.1 for grains). Well owners should test, since hardness varies well to well.
What size softener do most homes need?
A four-person home on 12-grain water needs roughly 3,600 grains per day, so a 32,000-grain unit regenerating about every eight days or a 48,000-grain unit for hard-water areas is typical. This calculator sizes from your actual numbers rather than a rule of thumb.
Do I need a drain nearby?
Yes — softeners discharge brine during regeneration and need a drain within reach plus a proper air gap. Running a new drain line is the most common reason installation quotes jump several hundred dollars.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Water Softener Installation Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/water-softener-installation-cost
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/water-softener-installation-cost" target="_blank" rel="noopener">Water Softener Installation Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Water Softener Installation Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/water-softener-installation-cost) (2026).