Calculator

Softener size calculator

People × daily gallons × hardness (gpg) × days between regenerations → rough grain capacity. Always recheck with a kit and your valve manual.

Result

Enter values and calculate

Output appears here: daily grains, capacity needed, and next common tank size.

Disclaimer

Starting estimate only—not a guarantee or engineering stamp.
Peak flow, iron bacteria, and valve type change real needs.
Install and main cuts may require a licensed plumber.
Common sizes used: 16k, 24k, 32k, 40k, 48k, 64k, 80k, 96k grains.

Formula: people × gpd × gpg × days between regenerations (optional iron adjustment). Sources and limits documented for editors in the repo tools formulas file.

Related guides & tools

essentialsHow to Choose a Water Softener (Size and Features)waterWater Hardness Explained (gpg, ppm, How to Test)startWhat Is Hard Water? (Signs, gpg, and What It Damages)systemsHow Water Softeners Work (Ion Exchange and Brine)toolsHardness unit converter

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