How Much to Run a Window AC in Massachusetts? $56/Summer
Running window air conditioner in Massachusetts costs about $0.34 an hour and roughly $56 for the summer — 1,100 W for 1.8 hours a day at 30.49¢/kWh.
· Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23
On this page: CalculatorTableHow we calculatedSources
Jump to calculator ↓Slider nudges the Massachusetts rate; the URL keeps it.
- Per hour
- $0.34 at 30.49¢/kWh
- Per summer
- $56 (92 days)
- Hours per day
- 1.8 (NOAA state cooling degree-days-scaled)
- Degree-days used
- 484 (NOAA CPC state, population-weighted)
- Wattage
- 1,100 W (typical 500–1,500)
- Massachusetts rate
- 30.49¢ (July 2026)
- Rank of 20 cold states
- 4 (4th most expensive)
Why this number
Massachusetts runs window air conditioner less than the national baseline in June–August — 1.8 hours a day on the NOAA state degree-day scaling used here, against 3.6 nationally — and pays 30.49¢/kWh for it. Those two numbers, times 1,100 W, are the whole $56.
Window air conditioner cost in Massachusetts by hours per day — per day / per summer
| Hours per day | Massachusetts avg 30.49¢ | NSTAR Electric Company 19.9¢ | Massachusetts Electric 23.1¢ | Direct Energy Services 15.1¢ |
|---|---|---|---|---|
| 1 h | $0.34 / $31 | $0.22 / $20 | $0.25 / $23 | $0.17 / $15 |
| 2 h | $0.67 / $62 | $0.44 / $40 | $0.51 / $47 | $0.33 / $31 |
| 4 h | $1.34 / $123 | $0.88 / $81 | $1.02 / $94 | $0.66 / $61 |
| 6 h | $2.01 / $185 | $1.31 / $121 | $1.52 / $140 | $1.00 / $92 |
| 8 h | $2.68 / $247 | $1.75 / $161 | $2.03 / $187 | $1.33 / $122 |
| 12 h | $4.02 / $370 | $2.63 / $242 | $3.05 / $281 | $1.99 / $183 |
What Massachusetts’s utilities charge for it
| Utility | Residential customers | ¢/kWh (EIA-861 2024) | Per hour | Per summer at 1.8 h/day |
|---|---|---|---|---|
| NSTAR Electric Company | 1,303,076 | 19.9¢ | $0.22 | $37 |
| Massachusetts Electric Co | 1,210,113 | 23.1¢ | $0.25 | $43 |
| Direct Energy Services | 498,718 | 15.1¢ | $0.17 | $28 |
What the numbers say about window air conditioner in Massachusetts
Massachusetts logged 484 population-weighted cooling degree-days over June–August (NOAA CPC state series), 51% of the CONUS figure of 958, which is why this page runs window air conditioner 1.8 hours a day against the national 3.6 — 1.8 hours less. At Massachusetts’s July 2026 rate of 30.49¢/kWh that makes it the 4th most expensive of the 20 cold states for window air conditioner: $56 for the 92-day summer, against Montana’s $14 and Alaska’s $68. NSTAR Electric Company, Massachusetts’s largest utility with 1,303,076 residential customers, averages 19.9¢ — $37 for the same hours — while Direct Energy Services at 15.1¢ comes to $28, a $9 spread on identical use. Massachusetts’s July 2026 rate of 30.49¢ sets the $0.34 per hour; its winter average of 30.88¢ is 0.39¢ higher, a difference that matters for heating loads but not for window air conditioner use in June–August.
Frequently asked questions
How much does it cost to run window air conditioner per hour in Massachusetts?
$0.34 an hour for a 1,100 W unit at Massachusetts’s July 2026 average of 30.49¢/kWh (1,100 ÷ 1,000 × 0.3049); at NSTAR Electric Company’s 19.9¢ it is $0.22.
How much does window air conditioner cost for the whole summer in Massachusetts?
About $56: 1,100 W × 1.8 hours a day × 92 days (June–August) × 30.49¢. The hours are the national 3.6 h/day scaled by NOAA CPC state population-weighted CDD, June–August 2026 (484 against the CONUS 958); enter your own hours above for your own figure.
Is window air conditioner expensive to run in Massachusetts compared with other cold states?
Massachusetts is the 4th most expensive of the 20 cold states on this site at $56 a summer; the range runs from Montana ($14) to Alaska ($68), driven almost entirely by the electricity rate.
How we calculated this
Worked for window air conditioner in Massachusetts: 1,100 W ÷ 1,000 × 0.3049 $/kWh = $0.34 per hour; hours per day = 3.6 × (484 ÷ 958) = 1.8; 1,100 ÷ 1,000 × 1.8 × 92 × 0.3049 = $56 for the summer. Rate: EIA Electric Power Monthly 5.6.A (July 2026); degree-days: NOAA CPC state population-weighted CDD, June–August 2026, against the CONUS total; utility prices: EIA-861 2024.Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.
Where to go next
- Cost to run window air conditioner (national page) — The 1,100 W and 3.6 h/day baseline this page scales for Massachusetts, with the sourced benchmark.
- Cost to heat a home in Massachusetts — Gas, propane, oil, heat pump and resistance per MMBtu at Massachusetts’s own prices — the whole-house picture.
- Find your electricity rate by ZIP — Massachusetts averages 30.49¢ but its utilities span the table above — send your own rate into this calculator.
- Solar panel cost in Massachusetts — Massachusetts’s 30.49¢ July rate, utilities and rate history on the solar side.
- Cost to run space heater in Massachusetts — Same Massachusetts rates and degree-days applied to a 1,500 W space heater.
- Cost to run heat pump in Massachusetts — Same Massachusetts rates and degree-days applied to a 3,500 W heat pump.
- Cost to run window air conditioner in Illinois — $57 for the summer at 19.22¢ and 2.9 h/day — the nearest cold-state comparison.
- Cost to run window air conditioner in Connecticut — $52 for the summer at 24.16¢ and 2.1 h/day — the nearest cold-state comparison.