Air Cooler Calculator: Room Size & Running Costs
Two questions decide whether an evaporative air cooler is right for you: will it cool in your climate, and what will it cost to run. This calculator answers both — then points you to the trending units that fit your market.
1 · Will an air cooler work in my room?
2 · Monthly running cost: air cooler vs portable AC
How the sizing verdict is calculated
Evaporative cooling lives and dies by humidity: the drier the air, the more water evaporates and the colder the outlet airflow. The calculator combines your humidity band with the room area and intended use to place you in one of three honest verdicts — good fit, works with expectations managed, or wrong tool, here's what to do instead. The mechanism is explained in full in our evaporative cooling explainer, and the buying criteria in the portable air cooler buying guide.
Where the trending units fit
Among the products on our board: in the UK, AiraBreeze (pure evaporative) and CoolJet (2-in-1 with heating) lead; in Germany, Vital Pro Breeze and AiraBreeze; in France, the USB-powered Froza AC. The four-way comparison settles the head-to-head.
Frequently asked questions
What size air cooler do I need for my room?
For personal evaporative units, match the format to the space: up to ~10 m² a desktop unit in your direct air path works well; 10–20 m² works as spot cooling with smart placement; beyond ~25 m² no portable evaporative unit will meaningfully cool the whole room — treat it as personal relief or consider AC.
Are air coolers cheap to run?
Yes — that's their strongest argument. Small evaporative units draw tens of watts versus several hundred to over a thousand for portable air conditioners, which is a 10–20× difference on the same hours of use. The calculator above puts real numbers on it at your electricity price.
Does the calculator work for air conditioners too?
The running-cost module compares any two wattages, so you can model an AC on either side. The sizing module is specific to evaporative coolers, whose usefulness depends on humidity in a way AC sizing does not.
Is my data stored when I use this calculator?
No. Everything runs locally in your browser; nothing is sent to a server or saved.