Water softener salt calculator
Use your softener's settings if you know them. Otherwise estimate from your water use and hardness.
How the math works
- From settings: lb per year = lb per regeneration × 365 ÷ days between regenerations.
- From water use (estimate): lb per year = people × gallons × gpg × 365 ÷ grains per lb of salt.
- Bags per year = lb per year ÷ bag size, rounded up. Cost = lb per year ÷ bag size × your price.
*8 lb is an example default: SoftenerParts.com, Frequency of Regeneration (salt per regeneration by resin volume) lists 8–10 lb per regeneration for 1 cu ft of resin and 6–12 lb as typical. Use your own setting. **40 lb is a common bag size; edit it to match yours. We don't show a salt price because prices vary by store and region; enter what you pay. Grains per lb (estimates) derive from Excalibur Water, C800X10 softening resin: 30,000 grains/cu ft at 15 lb salt, 20,000 grains at 6 lb: 20,000 ÷ 6 ≈ 3,333 and 30,000 ÷ 15 = 2,000.
Worked example
8 lb every 7 days: 8 × 365 ÷ 7 = 417 lb a year, about 35 lb a month. That's 10.4 bags of 40 lb, so buy 11. Multiply 417 ÷ 40 = 10.43 by your bag price for the yearly cost.
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FAQ
How much salt does a water softener use?
It depends on the salt dose and how often it regenerates. A unit using 8 lb every 7 days uses about 417 lb a year. SoftenerParts.com puts typical homes at 30–100 lb a month.
Does the efficient salt setting really save salt?
Resin specs show 6 lb of salt per cubic foot restores about 20,000 grains and 15 lb restores about 30,000, so the low dose gets two-thirds of the capacity from 40% of the salt.
How do I find my salt per regeneration?
Check the salt dose (lb) in your softener's settings menu or manual, or ask your installer.