Estimate the softener size your home needs from household size, local hardness, iron and regeneration schedule, using published sizing methods.
Enter the number of people in your home, your water hardness in grains per gallon (gpg), any iron from a water test, and how many days you want between regenerations. If you are on LVVWD water, the published hardness is 16 to 17 gpg (LVVWD); look up other areas with our hardness by city tool. The calculator estimates the grains your softener must remove and suggests a size based on its efficient-salt capacity.
Estimate the grain capacity your home needs. Results are estimates, not a quote.
A softener is rated by grain capacity, the total grains of hardness it can remove before it must recharge (NDSU Extension). Sizing follows a simple formula published by equipment supplier Nelsen Corp.:
Example, labeled as an illustration: a family of four on LVVWD water at 16.5 gpg uses about 234 gallons a day, or about 3,870 grains. Over 7 days that is roughly 27,100 grains.
The size on the label is the capacity at a full, heavy salt dose. Most softeners are programmed to use less salt per cycle, which yields less capacity. In Nelsen’s published table, a 32,000-grain unit delivers 24,000 grains at an efficient setting, a 40,000-grain unit 30,000 and a 48,000-grain unit 36,000, about 75% of nominal (Nelsen). Alberta Agriculture notes that a half salt dose restores a softener to roughly two-thirds of its maximum capacity (Alberta Agriculture).
In the example above, 27,100 grains at 75% efficiency points to a 40,000-grain softener rather than a 32,000.
32,000 nominal
24,000 efficient
40,000 nominal
30,000 efficient
48,000 nominal
36,000 efficient
64,000 nominal
48,000 efficient
Efficient-regeneration capacities from Nelsen Corp.’s softener sizing table; actual capacity depends on the model and salt setting.
Dissolved (ferrous) iron uses up resin capacity too. Nelsen adds 4 gpg of compensated hardness for every 1 ppm of iron and notes that softeners are typically rated for up to 2 ppm (Nelsen). Nebraska Extension warns that iron above 5 ppm can reduce a softener’s effectiveness (UNL). City water in the valley rarely needs this adjustment, but Pahrump well owners should test first and may need a dedicated iron and H2S filter.
See typical pricing in our Las Vegas water softener cost guide, or browse our Professional Series water softeners.
Using the assumptions above, about 27,000 grains per week, which points to roughly a 40,000-grain unit at an efficient salt setting. Higher water use or a shorter cycle changes the answer.
Yes. Nebraska Extension estimates about 8 mg/L of sodium per gpg of hardness removed (UNL). Many homes add a reverse osmosis faucet for drinking water.
Usually not. In many homes, irrigation and pool lines are plumbed to bypass the softener, so sizing is based on indoor use. Your installer can confirm how your plumbing is set up.
Not sure what is in your water or what equipment fits your home? Water Quality of Las Vegas offers a free water analysis and free estimates across the valley, from Henderson to Pahrump. Call or text 702-623-2724 any time, or request your free water analysis online.
