Calculate your cost
Start with the example below, then replace the wattage, daily runtime, and rate with the numbers for your humidifier.
This setup uses about 14 kWh in a 30-day month.
Please enter valid values within the ranges shown.
| Schedule | Hours/day | Cost/month |
|---|---|---|
| Half runtime | 6 | $1.36 |
| Page example | 12 | $2.71 |
| Longer runtime | 18 | $4.07 |
Same 40-watt input and 18.83¢/kWh rate; only runtime changes.
Formula for the page example
0.04 kW × 12 hr × $0.1883 = $0.09 per day
Convert watts to kilowatts, multiply by the active hours used each day, then multiply by the electricity price in dollars per kWh. Multiply the daily result by 30 for the monthly estimate shown above.
How to read this estimate
Ultrasonic and evaporative humidifiers use very little electricity, even when running all night. Warm mist models use a heating element and cost much more to run.
Use this as a baseline until you can check the label or measure the humidifier directly. Model, settings, condition, climate, and household routine can all change the result.
What changes the cost?
- 01
Type of humidifier (warm mist vs. cool mist)
- 02
Fan speed setting
- 03
Hours of operation per day
Ways to spend less
- Choose a cool mist model to avoid paying for water heating.
- Run it only when room humidity drops below 40%.
- Keep the tank and filters clean to ensure the fan runs freely.