How Much to Run a Mini Split in Montana? $0.27/Hr, $719/Winter
Running ductless mini-split in Montana costs about $0.27 an hour and roughly $719 for the winter — 2,000 W for 14.9 hours a day at 13.26¢/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 Montana rate; the URL keeps it.
- Per hour
- $0.27 at 13.26¢/kWh
- Per winter
- $719 (182 days)
- Hours per day
- 14.9 (NOAA state heating degree-days-scaled)
- Degree-days used
- 5,545 (NOAA CPC state, population-weighted)
- Wattage
- 2,000 W (typical 400–3,500)
- Montana rate
- 13.26¢ (October 2025–March 2026 average)
- Rank of 20 cold states
- 15 (15th most expensive)
Why this number
Montana runs ductless mini-split longer than the national baseline in October–March — 14.9 hours a day on the NOAA state degree-day scaling used here, against 9.4 nationally — and pays 13.26¢/kWh for it. Those two numbers, times 2,000 W, are the whole $719.
Ductless mini-split cost in Montana by hours per day — per day / per winter
| Hours per day | Montana avg 13.26¢ | NorthWestern Energy LL 14.2¢ | Adjustment 2024 12.2¢ | Flathead Electric Coop 9.7¢ |
|---|---|---|---|---|
| 1 h | $0.27 / $48 | $0.28 / $52 | $0.24 / $44 | $0.19 / $35 |
| 2 h | $0.53 / $97 | $0.57 / $103 | $0.49 / $89 | $0.39 / $71 |
| 4 h | $1.06 / $193 | $1.14 / $207 | $0.98 / $178 | $0.78 / $141 |
| 6 h | $1.59 / $290 | $1.70 / $310 | $1.46 / $266 | $1.16 / $212 |
| 8 h | $2.12 / $386 | $2.27 / $414 | $1.95 / $355 | $1.55 / $282 |
| 12 h | $3.18 / $579 | $3.41 / $620 | $2.93 / $533 | $2.33 / $424 |
What Montana’s utilities charge for it
| Utility | Residential customers | ¢/kWh (EIA-861 2024) | Per hour | Per winter at 14.9 h/day |
|---|---|---|---|---|
| NorthWestern Energy LLC - (MT) | 328,127 | 14.2¢ | $0.28 | $770 |
| Adjustment 2024 | 78,442 | 12.2¢ | $0.24 | $661 |
| Flathead Electric Coop Inc | 63,317 | 9.7¢ | $0.19 | $526 |
What the numbers say about ductless mini-split in Montana
Montana logged 5,545 population-weighted heating degree-days over October–March (NOAA CPC state series), 158% of the CONUS figure of 3,500, which is why this page runs ductless mini-split 14.9 hours a day against the national 9.4 — 5.5 hours more. At Montana’s October 2025–March 2026 average rate of 13.26¢/kWh that makes it the 15th most expensive of the 20 cold states for ductless mini-split: $719 for the 182-day winter, against Nebraska’s $552 and Maine’s $1,886. NorthWestern Energy LLC - (MT), Montana’s largest utility with 328,127 residential customers, averages 14.2¢ — $770 for the same hours — while Flathead Electric Coop Inc at 9.7¢ comes to $526, a $244 spread on identical use. Per million Btu delivered, this unit at the NEEP median COP of 2.17 costs $17.91 against $9.37 for natural gas at Montana’s winter average of $0.89/therm, which is the whole-house comparison the Montana heating page works through. Montana’s winter-average rate (13.26¢) sits 1.73¢ below its July 2026 reading of 14.99¢; the season figure uses the winter average because that is when ductless mini-split runs.
Frequently asked questions
How much does it cost to run ductless mini-split per hour in Montana?
$0.27 an hour for a 2,000 W unit at Montana’s October 2025–March 2026 average average of 13.26¢/kWh (2,000 ÷ 1,000 × 0.1326); at NorthWestern Energy LLC - (MT)’s 14.2¢ it is $0.28.
How much does ductless mini-split cost for the whole winter in Montana?
About $719: 2,000 W × 14.9 hours a day × 182 days (October–March) × 13.26¢. The hours are the national 9.4 h/day scaled by NOAA CPC state population-weighted HDD, October 2025–March 2026 (5,545 against the CONUS 3,500); enter your own hours above for your own figure.
Is ductless mini-split expensive to run in Montana compared with other cold states?
Montana is the 15th most expensive of the 20 cold states on this site at $719 a winter; the range runs from Nebraska ($552) to Maine ($1,886), driven almost entirely by the electricity rate.
How we calculated this
Worked for ductless mini-split in Montana: 2,000 W ÷ 1,000 × 0.1326 $/kWh = $0.27 per hour; hours per day = 9.4 × (5,545 ÷ 3,500) = 14.9; 2,000 ÷ 1,000 × 14.9 × 182 × 0.1326 = $719 for the winter. Rate: EIA Electric Power Monthly 5.6.A (October 2025–March 2026 average); degree-days: NOAA CPC state population-weighted HDD, October 2025–March 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 ductless mini-split (national page) — The 2,000 W and 9.4 h/day baseline this page scales for Montana, with the sourced benchmark.
- Cost to heat a home in Montana — Gas, propane, oil, heat pump and resistance per MMBtu at Montana’s own prices — the whole-house picture.
- Find your electricity rate by ZIP — Montana averages 13.26¢ but its utilities span the table above — send your own rate into this calculator.
- Solar panel cost in Montana — Montana’s 14.99¢ July rate, utilities and rate history on the solar side.
- Cost to run space heater in Montana — Same Montana rates and degree-days applied to a 1,500 W space heater.
- Cost to run heat pump in Montana — Same Montana rates and degree-days applied to a 3,500 W heat pump.
- Cost to run ductless mini-split in Colorado — $734 for the winter at 16.45¢ and 12.3 h/day — the nearest cold-state comparison.
- Cost to run ductless mini-split in Iowa — $703 for the winter at 13.1¢ and 14.7 h/day — the nearest cold-state comparison.