Choose your home water system by the numbers
Independent sizing calculators, certification data and analysis of thousands of customer reports. No sales calls, no "we tested it" theatre, just the math behind a good decision.
Water softener size calculator
Enter your hardness, iron and household size. Get the smallest standard unit that regenerates about once a week at a salt-efficient setting, plus salt cost per month.
Coming next
- Well-water treatment-train builder: iron, sulfur, manganese, pH, UV, RO in the right order.
- Generator and battery sizing for a well pump, sump pump, fridge and CPAP.
- NSF/ANSI certification table for 30+ softeners and whole-house filters.
- Brand comparisons built from specifications, certificates and review analysis: SpringWell, Kind, Aquasana, Crystal Quest, Fleck/Clack DIY.
How we work
We do not own or install these systems. We read specifications and NSF certificates, aggregate thousands of customer reviews, interview certified water specialists, and publish the method behind every number. Read the full methodology.