What a water softener costs to run

By Ajay Singh. Updated November 10, 2026.

For a typical family, a salt-based softener's running costs are mostly salt, then the water used to flush it, with electricity a few dollars a year. A household removing 3,000 grains of hardness a day uses roughly 9 to 14 bags of salt and around 1,700 to 2,300 gallons of regeneration water a year, depending on the salt setting. Put in your own prices below.

Where the numbers come from

Salt

Salt use depends on how much hardness you remove and how much salt the softener uses per regeneration. More salt recharges more of the resin, but with diminishing returns. Solenis, a water treatment chemicals company, says a dose of 15 lb per cubic foot of resin gives about 30,000 grains of capacity, which is about 2,000 grains per pound of salt. An article in Water Conditioning & Purification gives about 24,000 grains at 8 lb per cubic foot, about 3,000 grains per pound. The calculator uses those two figures for the full and low settings.

For comparison, softeners certified as "efficiency rated" under NSF/ANSI 44 reach at least 3,350 grains per pound of salt at their rated setting. If yours is one of them, its real salt use may be a little lower than the low-salt figure here.

We couldn't open a retailer's page to check a current salt price (the stores we tried blocked our requests), so enter what you pay.

Water

Each regeneration backwashes and rinses the resin and sends the brine to the drain. Penn State Extension and Nebraska Extension both estimate about 50 gallons per regeneration. Manufacturer figures we read were a little lower, around 44 gallons at maximum salt for Morton's M45C. How many regenerations you get depends on the softener's size and salt setting: a bigger softener on a full setting regenerates less often.

For the price, look at your water bill for the charge per 1,000 gallons (or per 100 cubic feet; 100 cubic feet is about 748 gallons). Add the sewer charge if it's based on water use. We couldn't find a reliable national average for water plus sewer per 1,000 gallons, so there's no default.

Electricity

The control valve on top of the tank uses very little. Pentair's service manual for the Fleck 5600 mechanical valve lists 3 watts maximum. We didn't find a published figure for electronic valves, so 3 watts is a starting point; check your own model's manual. The electricity default is the US average residential price for August 2026, according to the US Energy Information Administration: 18.16 cents per kWh. Your rate may be quite different, so swap in your own.

A worked example

Penn State's example household: 4 people using 75 gallons each a day at 10 gpg, so 3,000 grains a day, or 1,095,000 grains a year, with a 32,000-grain softener.

The low setting uses a third less salt but regenerates more often, so it uses more water. Salt usually costs more than the extra water, but put your own prices in and see.

Costs the calculator leaves out

• Buying and installing the softener. That's a separate, one-off cost.
• Resin cleaner. A. O. Smith's manual recommends a resin bed cleaner every six months if your water has iron.
• Repairs and parts over the softener's life.
• Septic considerations. Some places restrict softener discharge to septic systems. Connecticut's public health code, for example, prohibits it, so check your state and local rules.

Haven't chosen a size yet? Start with the softener size calculator. Weighing up a salt-free unit to avoid these costs? Read softener vs conditioner first: a conditioner doesn't remove hardness.