Free calculator
Air Purifier Electricity Cost Calculator: What Does It Cost to Run?
Enter the watts, hours of use and your electricity rate to see what an air purifier costs per day, month and year, including replacement filters.
An air purifier only works while it runs, and the best results come from running it all the time. This calculator shows what that costs, so you can compare models on running cost as well as purchase price.
How the calculator works
Energy per day (kWh) = watts × hours per day ÷ 1,000
Cost = kWh × your price per kWh
A month is 365 ÷ 12 = 30.4 days. The default price is the latest US average residential rate from the EIA: 18.31 cents per kWh in July 2026. Your own rate is on your electricity bill and can be much higher or lower depending on your state.
If you enter a filter price and how many filters you replace each year, the calculator adds them to the yearly total. Filter intervals are in each purifier’s manual; many models also show a filter light.
Worked examples
| Purifier | Hours per day | Energy | Cost at 18.31¢/kWh |
|---|---|---|---|
| 30 W (a typical medium speed) | 24 | 0.72 kWh/day | about $4.01 a month, $48.12 a year |
| 50 W | 24 | 438 kWh/year | about $6.68 a month, $80.20 a year |
| 45 W | 24 for 30 days | 32.4 kWh | about $5.93 for the month |
| “Standard” room air cleaner (ENERGY STAR estimate) | 24 | 394 kWh/year | about $72 a year |
Where to find the watts
- The manual or spec sheet often lists power for each fan speed. Use the speed you’ll run most often, which is usually not the highest.
- The ENERGY STAR product finder lists certified models with their efficiency.
- A plug-in power meter measures the real draw at each setting.
Note: The top speed is what gives the CADR on the box, but it is also the loudest and uses the most power. A larger purifier on a low speed can clean the same room for less noise and similar running cost. Use the air purifier size calculator to find the CADR your room needs.
Lowering the running cost
- Choose an ENERGY STAR model: since October 2025 the program requires at least 4.4 to 5.6 cfm of PM2.5 CADR per watt, depending on size.
- Size the purifier so it can run on a medium speed instead of maxed out.
- Keep the pre-filter clean and replace the main filter on schedule; a clogged filter makes the fan work harder for less clean air.
- Compare filter costs before you buy. For many purifiers, replacement filters cost more per year than electricity. Our guide to the air purifier with washable filters explains which parts can be washed and which must be replaced, and the best HEPA air purifiers under $100 compares budget models.
Frequently asked questions
How much electricity does an air purifier use?
It depends on the model and fan speed. ENERGY STAR estimates that a standard room air cleaner running all the time uses about 394 kWh a year, and that certified models use more than 50% less. Check the watts for each speed in the manual.
How much does it cost to run an air purifier 24/7?
A 50-watt purifier running around the clock uses 438 kWh a year. At the US average residential price of 18.31 cents per kWh (EIA, July 2026), that is about $80 a year, or $6.68 a month.
Do air purifiers use a lot of electricity?
Usually less than people expect. Most of the time a purifier runs on a low or medium speed that draws far fewer watts than its top speed. Replacement filters often cost more per year than the electricity.
Is an ENERGY STAR air purifier worth it?
If you run a purifier all day, efficiency adds up. ENERGY STAR says certified models save about 211 kWh a year compared with standard ones, roughly $18 to $40 a year depending on electricity prices.