What does an air purifier cost to run?

Run the numbers on your own use

Change any of these and the figures update. The defaults are the typical case described above; your rate is the input that moves the answer most.

Why this is lower than the number you will see elsewhere

Almost every published answer to this question multiplies the rating on the label by the hours the appliance is switched on. For an air purifier that gives 394 kWh a year, or $72.

A fan at a fixed speed draws steadily. Units on an automatic setting drop to a low speed when the air is clean, which is where most of the variation comes from.

The arithmetic, step by step

Nothing here is hidden, so you can check it or change it. Working in the order the formula runs:

1. 45 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 100% — the share of its in-service time it is really pulling that. A fan at a fixed speed draws steadily. Units on an automatic setting drop to a low speed when the air is clean, which is where most of the variation comes from.
   That gives 45 W averaged across the hours it is on.
3. × 24 hours a day × 365 days — A room unit on a medium setting, running continuously.
   45 × 24 × 365 ÷ 1,000 = 394 kWh a year.
4. × 18.34¢ — the US average residential rate for June 2026.
   394 kWh × 18.34¢ = $72 a year.

Change any assumption in the calculator above and every figure on this page moves with it. The two that matter most are your rate, which varies 4× across the country, and the hours — the duty cycle is a property of the appliance, but the hours are a property of you.

How sensitive is that number?

A single figure invites more confidence than it deserves. Here is the same appliance under assumptions either side of the default, so you can see how much of the answer is the appliance and how much is the guess about how you use it.

Everything else held at the default. The spread here is the honest error bar on the headline figure.

What it costs per hour, day and month

At 18.34¢ per kWh, the US residential average for June 2026.

The thing worth knowing

Small draw, but no off switch in practice — people buy these to run all the time, which turns 45 W into a real annual figure. Fan speed is the whole story: the draw roughly follows the cube of airflow, so running one on medium instead of high can cut its consumption by more than half while still turning the room’s air over several times an hour.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this air purifier costs $208 a year in Hawaii and $52 in Nevada — a difference of 4×.

Cost of running one air purifier for a year, by state. Residential average price, EIA June 2026.

Other tools, hobbies and outdoors costs

• Crypto mining rig

  $4,820 a year

  A single ASIC unit running around the clock.

• Oxygen concentrator

  $375 a year

  A stationary home unit at a moderate flow rate, sixteen hours a day.

• Pottery kiln

  $190 a year

  A medium studio kiln fired roughly twice a month to cone 6.

• Electric fireplace

  $97 a year

  Evenings through winter with the heater on.

• Home server or NAS

  $96 a year

  A four-bay NAS running continuously.

• Radon mitigation fan

  $96 a year

  A typical sub-slab depressurisation fan running as installed.

Questions

Source: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A, June 2026. U.S. Government work, public domain.

How every figure on this page is computed · Where the data comes from