Size your water softener with real math, not a sales pitch.
Size your water softener with real numbers: your hardness, your household, the math shown.
Open the sizing calculator Read the guides
✓ Specs and prices cited to official pages, with dates ✓ NSF listings checked at the source ✓ No hands-on testing claims
Know your water
Find your hardness in your utility's annual water quality report, or test a private well at a state-certified lab.
How to find it →Run the numbers
Grains per day, recommended capacity, and regeneration interval, with gpg/ppm conversion and an iron adjustment.
Calculator →Check the certificate
Look up NSF/ANSI claims in NSF's own listings. "Certified components" isn't the same as a certified system.
Certifications →Latest guides
How to Find Your Water Hardness: Water Reports, Test Strips, and Lab Tests
Where to find your hardness number, how to convert ppm/mg/L to grains per gallon, and when a certified lab test is the right move.
Read the guide →Sizing mathHow to Size a Water Softener: Grains Per Day Math, Step by Step
Work out grains per day from your hardness and household, pick a capacity, and check flow rate. Worked examples plus dated prices from official pages.
Read the guide →CertificationsNSF/ANSI 42, 44, 53, 58, 61: What Water Treatment Certifications Mean
A plain-English guide to the NSF/ANSI standards on softeners and filters, the difference between certified systems and certified components, and how to check a listing.
Read the guide →Health note: Not health or medical advice. A water softener treats hardness; it is not a health device. To know what is in your water, read your utility’s annual water quality report (Consumer Confidence Report) or, for a private well, get a test from a state-certified lab. For health questions, talk to your local health department or doctor.