WattNoteAir purifier electricity and filter cost guide
Your appliance’s estimated energy cost
What this estimate uses
Calculation method and limits
Watts ÷ 1000 × hours × days gives energy. Multiply per-cycle energy by cycles; annual energy is used directly. Monthly and daily averages divide the annual estimate by 12 and 365. Seasonal bills, changing fixed charges, tiers and time-of-use rates are not predicted. Maximum label watts may differ from average power.
Use the detailed calculator
Calculate with your own usage
Formula reviewed: 2026-09-19 · Inputs: your measurements or product labels, not an official tariff database.
Calculate electricity from average watts, then account for filter costs separately in the ownership calculator.
Automatic mode varies
Maximum rated watts may differ from daily average power. Divide measured kWh over several normal days by measured hours and multiply by 1000 to estimate average watts.
Compare equivalent cleaning conditions
Coverage, airflow and filter condition affect performance. Electricity alone cannot compare cleaning effectiveness; lower fan speed is not always appropriate.
Illustrative arithmetic
30 average watts × 24 hours/day × 30 days/month × 12 months/year = 259.2 kWh/year. At 0.2 currency units/kWh this is 51.84 currency units/year. This hypothetical example assumes 360 operating days.
Include replacement filters
Multiply filter price by actual annual replacement count to estimate maintenance. My Home lets you record a verified replacement date and export it to your calendar.