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Room Humidifier Cost Calculator

Cool-mist humidifiers usually draw little power, while warm-mist models can use much more because they heat water.

35 W starting input 8 hr/day No sign-up

Typical starting estimate

$1.55/month8.4 kWh at 18.44¢/kWh

Your inputs

Calculate operating cost

watts
hours
days
$/kWh
EIA residential average price, not a utility-specific rate. Your bill’s all-in rate gives the best personal estimate.

Live estimate

Estimated monthly cost$1.55at 18.44¢ per kWh
Per day$0.05
Per year$19
Monthly use8.4 kWh
Transparent calculation(35 W ÷ 1,000) × 8 hr × 30 days × $0.184/kWh

Actual use can differ when equipment cycles or changes power. Measure at the wall when precision matters.

How the humidifier estimate works

The calculator converts watts to kilowatts, multiplies by effective runtime, and then applies the electricity price. With the starting inputs, this humidifier uses about 8.4 kWh per month.

35 W ÷ 1,000 × 8 hours × 30 days × $0.1844/kWh = $1.55

Technology type, fan speed, humidity target, and mineral buildup determine the actual draw and runtime.

How runtime changes the estimate

Daily runtimeMonthly useMonthly cost
1 hour/day1.1 kWh$0.19
4 hours/day4.2 kWh$0.77
8 hours/day8.4 kWh$1.55

These scenarios assume the device draws the full starting wattage for the entire runtime. Cycling and variable-speed equipment should use effective runtime or measured kWh.

Estimated monthly cost in high-price states

State2026-05 average priceEstimated cost
Hawaii52.00¢/kWh$4.37/mo
California33.25¢/kWh$2.79/mo
New York29.93¢/kWh$2.51/mo
Rhode Island29.46¢/kWh$2.47/mo

Practical ways to reduce cost

  • Use a hygrometer to avoid over-humidifying.
  • Clean the unit as directed.
  • Choose evaporative or ultrasonic operation when appropriate.

Compare related equipment

Space Heater180.0 kWh/mo →Window Air Conditioner240.0 kWh/mo →Dehumidifier120.0 kWh/mo →Heat Pump600.0 kWh/mo →

Frequently asked questions

How much electricity does a humidifier use?

Using a 35-watt starting input for 8 hours per day and 30 days per month produces an estimate of 8.4 kWh per month. Actual use can differ because equipment may cycle or change power.

How much does it cost to run a humidifier each month?

At the latest 2026-05 U.S. residential average price of 18.44 cents per kWh, the starting estimate is $1.55 per month. Replace the inputs with your own numbers for a personal estimate.

What number should I use for the electricity price?

Divide the total electric charges on your latest bill by the total kWh used for an all-in price. State averages are useful for comparison but are not utility-specific rates.

Data source

U.S. Energy Information Administration, Electricity Retail Sales, residential average price. Latest monthly data: 2026-05; comparison baseline: 2025 annual. Verified 2026-08-05. Monthly prices can vary seasonally and are not utility-specific rates.

View EIA data