Home systems running cost by state

What a sauna, an air purifier and a water softener actually cost to keep running, in your state and in all fifty-one. Electricity rates are EIA's published residential figures; the salt arithmetic comes from the NSF efficiency floor. Every step is shown, and the one thing that most calculators get quietly wrong is flagged where it bites.

Disclosure and scope. This page contains affiliate links; we may earn a commission on qualifying purchases at no cost to you. This tool multiplies published rates by usage figures you supply. It is an estimate for comparison, not a prediction of your bill — and the notes below explain precisely why no honest tool can promise otherwise.

Your electricity rate

EIA residential average, June 2026. Every state is compared in the results regardless of what you pick here.
Your own bill beats any average. See the note in the results about which number to take off it.
Your assumption, not a published figure. A thermostat cycles the element; nobody publishes the fraction.
58.6 is the metered indoor figure. The trade sizes on 75. Try both.
3,350 is the NSF/ANSI 44 floor for an efficiency-rated unit. A unit that is not efficiency rated will do worse.

Where these numbers come from

The rates and the efficiency floor are published figures, linked below. The usage numbers are yours. Everything in between is multiplication, shown in full so you can check it.

  1. Electricity rates. EIA Electric Power Monthly, average price of electricity to ultimate customers by end-use sector, residential, by state — June 2026, with a US average of 18.34 cents per kilowatthour. EIA Electric Power Monthly, Table 5.6.A
  2. What that rate actually is. EIA's own glossary: average revenue per kilowatthour "is calculated by dividing the total monthly revenue by the corresponding total monthly sales for each sector and geographic area." It is an average of revenue over sales, not a tariff, and it therefore has every fixed monthly charge baked into it. EIA glossary
  3. Salt efficiency. Department of Energy, Building America Solution Center, reproducing NSF/ANSI 44: an efficiency-rated softener must have "a rated salt efficiency of not less than 3,350 grains of total hardness exchange per pound of salt" and must "not generate more than 5.0 gallons of water per 1,000 grains of hardness removed during the service cycle." Building America Solution Center
  4. Household water volume. The default of 58.6 gallons per person per day is the metered indoor figure from the Water Research Foundation's Residential End Uses of Water, Version 2, across 23 utilities. The trade convention is 75. WRF project 4309
  5. Filter replacement. EPA states that all filters need regular replacement and that a dirty, overloaded filter will not work well; for furnace filters its guide notes manufacturers typically recommend replacement every 60 to 90 days. Portable air cleaner filter life is a manufacturer claim, and the runtime it assumes is rarely published. EPA Guide to Air Cleaners in the Home (PDF)
  6. The sauna duty cycle is not a published figure. A heater cycles on a thermostat once the room is at temperature, and no manufacturer we have found publishes the fraction of full draw that averages out to. It is an input you set, it is labelled as an assumption everywhere it appears, and it is the largest single source of error in the sauna figure.

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