Estimate softener size
This calculator is a planning estimate. It helps you understand the relationship between hardness, household water use, and softener capacity before comparing systems or installer quotes.
75 gallons per person per day is a common planning assumption. Your actual usage may differ.
How the estimate works
The basic sizing logic is:
The result is an estimated grain load before regeneration. In practice, installer recommendations may also account for iron, efficiency settings, peak flow, plumbing layout, and local rules.
Important limitations
This calculator does not recommend a specific product. It does not account for iron, manganese, private-well chemistry, unusual water use, flow-rate requirements, or local code requirements. Use it to understand the scale of the problem, then confirm with a qualified installer or water professional.
Sources and assumptions
- Hardness conversion: 1 grain per gallon ≈ 17.1 mg/L as calcium carbonate.
- Water use is user-entered; default is a planning assumption, not a measured value.
- Capacity result is rounded up to common nominal softener-size tiers.