A 3-ton central air conditioner in Kansas costs about $111.51 in July and $364 a year at 15.26¢/kWh; an 8,000 BTU window unit about $21.80 in July.
At 15.26¢/kWh — Kansas average, Jan–Aug 2026 (EIA). That is 16% below the U.S. average of 18.19¢.
| Efficiency | Per year | vs yours |
|---|---|---|
| SEER2 13.4 (min · North) | $364 | — |
| SEER2 14.3 (min · South) | $341 | −$22.93 |
| SEER2 15.2 (ENERGY STAR) | $321 | −$43.15 |
| SEER2 17 (ES average) | $287 | −$77.16 |
| Month | Full-load hours | 3-ton central | 8,000 BTU window |
|---|---|---|---|
| March | 4 | $1.77 | $0.35 |
| April | 9 | $3.54 | $0.69 |
| May | 60 | $24.78 | $4.85 |
| June | 175 | $71.56 | $13.99 |
| July | 272 | $111.51 | $21.80 |
| August | 242 | $99.12 | $19.38 |
| September | 108 | $44.25 | $8.65 |
| October | 18 | $7.33 | $1.43 |
DOE's room-AC test assumes 750 full-load hours a year for a typical U.S. home. We scale it by Kansas's population-weighted cooling degree days (1,441 ÷ 1,216) and spread it over the months the same way: 889 hours a year. Your thermostat setting and insulation move this a lot — switch the calculator to your own hours if you know them.
3 tons = 36,000 BTU/h ÷ SEER2 13.4 = 2,687 W. × 889 h = 2,388 kWh × 15.26¢ = $364.
The full method, material data and tips are on the main air conditioner cost calculator page.