The short answer
- About $651 to own over five years: $240 to buy, $191 in electricity, $220 in filters.
- One filter set, two expiry dates. The deodorisation filter is rated six months, the HEPA twelve.
- 361 sq ft at 4.8 air changes an hour, published by Coway rather than calculated by us.
Who this is for
The Mighty is the sensible default for a room up to roughly 360 square feet. It has a full AHAM CADR listing for all three particle types, it costs $239.99 from Coway, and its filters are the second cheapest to feed in this set.
Credit where it is due: Coway prints 361 square feet at 4.8 air changes an hour directly on the product page, alongside the 1,748 square feet at one air change. That is the honest number, and we did not have to derive it.
What the specifications actually say
CADR is 233 for smoke, 246 for dust and 240 for pollen. That is within a couple of points of the Levoit Core 400S, for which it draws 77 W against the Levoit’s 38 W. Twice the electricity for the same cleaning rate is the trade you are making, though as the model below shows, electricity is not where this category hurts.
The detail worth knowing before you buy: Coway rates the HEPA filter at twelve months and the deodorisation filter at six, and sells them as a single set. Follow the shorter interval and your filter spend doubles. Follow the longer one and you are running a spent carbon filter for half of every year. Coway does not resolve this for you.
| Specification | Value | Source |
|---|---|---|
| CADR (smoke) | 233 CFM | Coway spec page, AHAM figures as published, retrieved 31 Aug 2026 |
| CADR (dust) | 246 CFM | Coway spec page |
| CADR (pollen) | 240 CFM | Coway spec page |
| Coverage at 1 ACH | 1,748 sq ft | Coway spec page |
| Coverage at 4.8 ACH | 361 sq ft | Published by Coway, not calculated by us |
| Power draw | 77 W | Coway spec page; no per-speed figures published |
| HEPA filter life | 12 months | Coway spec page |
| Deodorisation filter life | 6 months | Coway spec page |
| Replacement filter set | $54.99 (list $64.99) | Coway store, retrieved 31 Aug 2026 |
| Noise | 24-53 dB(A) | Coway spec page |
| Price | $240 | Merchant listing at publication |
The cost nobody quotes
Five years, at the US average of $0.17 per kWh, running eight hours a day. We have costed one set a year, which follows the HEPA schedule rather than the carbon one.
What it really costs over 5 years
Total$651
| Cost | Amount | How we got it |
|---|---|---|
| Purchase price | $240 | Street price at publication |
| Electricity | $191 | 224 kWh/yr at $0.17 per kWh |
| Filters & consumables | $220 | $44 per year |
| Total | $651 | $130 per year · $0.04 per session |
Running costs are 63% of the 5-year total. The sticker price is not the decision.
Electricity priced at $0.17 per kWh, the US residential average. Change the rate in the settings to match your utility. Consumable costs come from the manufacturer's published replacement schedule.
On an annual set, filters come to about $220 across five years. If you replace on the six-month deodorisation schedule instead, that line roughly doubles to $440 and the five-year total goes past $870, which would move this machine from second cheapest to fourth. The interval you choose matters more than the price you paid.
Electricity is $191 over the five years, at 224 kWh a year. That is the highest of the sub-$400 machines here, and it is the price of that 77 W rating.
Certifications, and what they cover
Frequently asked questions
How often should the Airmega Mighty filters be replaced?
Coway rates the HEPA filter at twelve months and the deodorisation filter at six, and sells both as one set. Our model costs one set a year, which follows the HEPA schedule.
What does it cost to run per year?
About $38 in electricity at $0.17 per kWh, running eight hours a day (77 W x 56 h/week x 52 = 224 kWh).
What room size does it really cover?
361 square feet at 4.8 air changes an hour, a figure Coway publishes itself.
Why do you not test these yourself?
We are a research publication, not a lab. We verify third-party test data, publish the source next to every number, and calculate the costs manufacturers leave out.
