Ductless Mini-Split vs Window Air Conditioner: Which Costs Less to Run?
The premium room-cooling option versus the budget classic: an inverter mini-split against a window unit.
Ductless Mini-Split · per month
$36.58
8 hours/day · 400–2,000 W
Window Air Conditioner · per month
$41.15
8 hours/day · 500–1,500 W
Verdict
The mini-split typically cools the same room for one-third to one-half the electricity, runs quieter, and heats in winter too. The window unit wins on upfront cost by a factor of five or more. High electricity rates and year-round use favor the mini-split's payback; occasional summer use in a cheap-power state favors the window unit.
Side by side
| Ductless Mini-Split | Window Air Conditioner | |
|---|---|---|
| Typical power | 400–2,000 W | 500–1,500 W |
| Typical usage | 8 hours/day | 8 hours/day |
| Energy per month | 195 kWh | 219 kWh |
| Cost per month (US avg) | $36.58 | $41.15 |
| Cost per year (US avg) | $439 | $494 |
| Cost per month in Hawaii | $90.66 | $102 |
Rates as of April 2026. Adjust the assumptions on each appliance's page: Ductless Mini-Split · Window Air Conditioner.
Frequently asked questions
Which is cheaper to run: a ductless mini-split or a window air conditioner?
At typical usage and the current U.S. average rate (18.8¢/kWh), the ductless mini-split is cheaper: about $36.58/month versus $41.15/month for the window air conditioner — a difference of $4.57 per month.
How much could I save per year by choosing the ductless mini-split?
About $54.87 per year at typical usage and average rates. In Hawaii (46.6¢/kWh) the annual gap grows to roughly $136.
Do these numbers apply to my state?
The ratio between the two stays the same everywhere, but the dollar gap scales with your rate — from North Dakota at 12.4¢/kWh to Hawaii at 46.6¢/kWh. Open each appliance's page for the exact cost in your state.