What it costs to run, and which half of that we can prove

Two numbers come out of this page. One is arithmetic on two published figures and is as solid as anything on this site. The other needs to know how many hours a year your unit runs, which nobody publishes for your house — so it arrives with a band and a label rather than false precision.

Running-cost worksheet

Heating in New York, per 1,000 hours of run time

$460

Cooling costs $236 for the same 1,000 hours. Both figures are pure arithmetic on two published numbers — the efficiency threshold and New York’s average residential price of 29.93 cents per kilowatt-hour. Nothing is assumed to produce them.

Draw while cooling at the rating point0.79 kW
Draw while heating at the rating point1.54 kW

Cooling hours we assume (720 cooling degree days x 0.8)576 h
Heating hours we assume (5,922 heating degree days x 0.3)1,777 h
Cooling electricity for the year455 kWh
Heating electricity for the year2,734 kWh

A full year lands near $954, and honestly it could be anywhere from $620 to $1,288. That band exists because the two run-hour coefficients above are ours, not anybody’s published figure. Trust the per-hour numbers; treat the annual one as a sketch.

What moves this most: the heating season — in this state the heat pump runs far more hours warming the room than cooling it, so the HSPF2 number matters more than the SEER2 number.


Your state, your equipment

State

Sets both the electricity price and the weather.

Head size

Use the figure the sizing tool gave you, not the one on the box.

Efficiency the unit is certified to

The same head, five climates

Every row below is a 12,000 BTU/h ENERGY STAR head — identical equipment — run through the same engine with only the state changed. The spread is not about the machine. It is about the price of electricity where you live and how many hours the weather asks the machine to work.

StateCents per kWhHeating, per 1,000 hCooling, per 1,000 hAssumed hours, heat / coolAnnual band
Maine28.63$440$2262,294 / 230$690$1,434
New York29.93$460$2361,777 / 576$620$1,288
California33.25$512$263754 / 766$382$792
Texas16.44$253$130456 / 2,571$292$606
Florida15.17$233$120186 / 3,118$271$563

Maine and Florida are the instructive pair. Maine has more than twenty-five times the heating degree days and a fraction of the cooling; Florida is the mirror image. Yet because California’s electricity costs roughly double what Florida’s does, California’s cost per run hour is higher than either. Any national average annual figure is therefore averaging across a spread this wide, which is why this site does not publish one.

The arithmetic, written out

SEER2 and HSPF2 are both expressed in BTU per watt-hour, which makes the conversion direct rather than mysterious. Divide the rated capacity by the efficiency figure and by a thousand and you have the draw in kilowatts:

draw (kW) = rated BTU/h / (efficiency x 1000)
cost per 1,000 hours = draw x 1,000 x state price per kWh

A 12,000 BTU/h head at the federal minimum 14.3 SEER2[2] draws 0.84 kW while cooling. The same head built to 15.2 SEER2 [3] draws 0.79 kW. At the national average residential price of 18.44 cents per kilowatt-hour[1], that difference is worth about $9 per thousand cooling hours. Whether that repays the price step depends on your hours, which brings us to the part we cannot prove.

To get from an hourly cost to a yearly one you need equivalent full-load hours. Utility Technical Reference Manuals publish those, by city, for exactly this purpose. We tried to obtain one at a stable public address on the retrieval date and failed. Rather than quietly picking a number and printing a confident annual bill, this site multiplies your state’s degree days by two coefficients of our own — 0.8 [5] for cooling and 0.3[6] for heating — and puts a 35 percent band[7] around the result. If your utility publishes a load-hours figure for your city, use theirs. It is better than ours and we would rather say so than pretend otherwise.

One more thing the arithmetic quietly assumes: SEER2 and HSPF2 are seasonal averages measured on a test bench across a defined range of outdoor conditions. A real January morning at five degrees is well outside the range that produced the HSPF2 number, which is why the cold-climate page exists as a separate check rather than a footnote here.


Questions people actually ask about this

Are mini-splits cheap to run?

Per hour, yes — a 12,000 BTU/h ENERGY STAR head draws well under a kilowatt while cooling. Per year is a different question entirely, and it depends far more on how many hours you leave it running than on which unit you bought.

Why do you give a cost per 1,000 hours instead of a monthly bill?

Because the per-hour figure is provable and a monthly bill is not. Capacity divided by the certified efficiency gives the draw in kilowatts; multiply by your state's published price and you have a number with no assumption in it. Run hours are the guess, so we keep the guess visibly separate.

Where do the annual run hours come from?

From your state's NOAA degree days multiplied by a coefficient we chose ourselves: 0.8 for cooling and 0.3 for heating. We could not obtain a citable utility Technical Reference Manual table, so those two numbers are ours and are labelled assumed everywhere they appear.

Why is there no estimate for Alaska, Hawaii or DC?

NOAA's statewide degree-day series does not cover them. Their electricity prices are published, so the per-hour figures still work; the annual estimate does not, and borrowing a neighbouring state's weather to fill the gap would be inventing data.

Where each figure on this page came from

  1. U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A (May 2026 data, released July 23, 2026) — https://www.eia.gov/electricity/monthly/epm_table_grapher.php?t=epmt_5_6_a (retrieved 2026-08-06)
  2. 10 CFR 430.32(c)(5), Energy and water conservation standards — https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-430/subpart-C/section-430.32 (retrieved 2026-08-06)
  3. ENERGY STAR (U.S. EPA), Air-Source Heat Pumps key product criteria — https://www.energystar.gov/products/heating_cooling/heat_pumps_air_source/key_product_criteria (retrieved 2026-08-06)
  4. ENERGY STAR (U.S. EPA), Air-Source Heat Pumps key product criteria — https://www.energystar.gov/products/heating_cooling/heat_pumps_air_source/key_product_criteria (retrieved 2026-08-06)
  5. minisplitcostcalculator.com — our own labelled adjustment, disclosed on the methodology page — https://minisplitcostcalculator.com/methodology/ (retrieved 2026-08-06) [our assumption — no direct source]
  6. minisplitcostcalculator.com — our own labelled adjustment, disclosed on the methodology page — https://minisplitcostcalculator.com/methodology/ (retrieved 2026-08-06) [our assumption — no direct source]
  7. minisplitcostcalculator.com — our own labelled adjustment, disclosed on the methodology page — https://minisplitcostcalculator.com/methodology/ (retrieved 2026-08-06) [our assumption — no direct source]

Rows in the state table above cover 48 of 51 jurisdictions for the annual estimate; the rest carry a price but no published degree days.