Running costs
Water softener salt cost calculator
Estimate how much salt your softener will use in a year, and what it will cost.
Your home
Start frompeople
gpg
gal/person/day
grains/lb
$
Salt cost$110 a yearAt your bag price
Salt548 lbper year
Bags13.740 lb each
The math
- 4 × 75 gal = 300 gallons a day
- 300 × 15 gpg = 4,500 grains a day
- 4,500 ÷ 3,000 grains/lb × 365 = 548 lb a year
- 548 ÷ 40 = 13.7 bags × $8 = $110
The formula
pounds per year = people × gallons per person per day × grains per gallon ÷ grains per pound of salt × 36575 gallons per person follows the EPA's figure of about 300 gallons a day for an average family. Softener spec tables commonly work out to about 2,100 to 3,900 grains per pound, and lower salt settings are more efficient. Bags typically cost $5 to $10.