How much does it cost to run a 12,000 BTU mini-split?

Data checked October 2026

Short answer

A 12,000 BTU mini-split draws about 0.53 kW and costs $0.10 an hour running — about $71.77 over a 750-hour U.S.-average cooling year at 18.19¢/kWh.

Power = capacity ÷ efficiency: 12,000 BTU/h ÷ SEER2 22.81 = 526 W.
DOE rates room air conditioners on 750 full-load hours a year; spread by U.S. cooling degree days that peaks in July at about 6.4 hours a day — $18.95 that month.
Inverter mini-splits run at part speed most of the time, which is why their seasonal rating is so much higher than their full-speed EER2 (12.79).
In a hot state the same unit runs far more: Texas has 2.2× the U.S. cooling degree days, Florida 2.8×. Pick your state in the calculator.

Adjust it to your exact job

Your air conditioner

Type

Size

SEER2

ENERGY STAR mini-splits around 12,000 BTU average SEER2 22.81.

How much it runs

Run time

750 full-load hours a year: DOE's 750-hour national basis × 1,216 cooling degree days in the U.S. ÷ 1,216 U.S.

Electricity rate

Where you live

Price per kWh

EIA's state average: total residential revenue ÷ kWh sold, so delivery and fixed monthly charges are spread over every kWh.

12,000 BTU mini-split in July

$18.95a month

$71.77 a year (395 kWh) · $0.10 per hour running

At 18.19¢/kWh — U.S. average, Jan–Aug 2026 (EIA).

Per hour running: $0.100.53 kW average draw
Busiest month (Jul): 6.4 hfull-load hours a day
Per year: $71.77750 full-load hours
Capacity: 12,000BTU/hSEER2 22.81

Estimated monthly cost in the U.S.

Same use, other efficiency

Yearly cost by efficiency rating
Efficiency	Per year	vs yours
ENERGY STAR average (SEER2 22.81)	$71.77	—
SEER2 18	$90.95	+$19.18

How to cut it

Raise the thermostat a few degrees and run a ceiling fan instead — an ENERGY STAR fan uses about 35 W on high.
Change the filter and keep the outdoor coil clear of leaves and grass so the system moves heat as rated.
Close blinds on sun-facing windows in the afternoon, when cooling hours peak.

Energy budget

395 kWh 12,000 BTU mini-split — cooling season electricity750 full-load hours at 18.19¢/kWh$71.77

Estimated total$71.77

Did this answer your question?

Compare

Every size at 18.19¢/kWh and 750 full-load hours a year

Size	Efficiency	Watts	Per hour	Per year
9,000 BTU	SEER2 22.81	395	$0.07	$53.83
12,000 BTU	SEER2 22.81	526	$0.10	$71.77
18,000 BTU	SEER2 22.81	789	$0.14	$108
24,000 BTU	SEER2 22.81	1,052	$0.19	$144

How this was worked out

12,000 BTU/h ÷ 22.81 = 526 W = 0.526 kW. × 18.19¢ = $0.10 per running hour. × 750 hours = $71.77 a year.

Prices are EIA's U.S. average residential price for Jan–Aug 2026. Efficiency figures are ENERGY STAR certified averages (window units) or the federal minimum shown.

The full method, material data and tips are on the main air conditioner cost calculator page.

Similar jobs

Other sizes people check

Sources

Data behind this answer

EIA Electric Power Monthly, Tables 5.6.A & 5.6.B — residential price by state (August 2026) — latest month and Jan–Aug 2026 year-to-date average for every state; preliminary, refreshed monthly · checked October 2026
ENERGY STAR certified room air conditioners (dataset) — average CEER by size for window units; 750 hours/yr label basis · checked October 2026
ENERGY STAR certified central AC & heat pumps (dataset) — 3-ton split average SEER2 17.06 / EER2 11.49 / HSPF2 8.44; 12k mini-split SEER2 22.81 · checked October 2026
10 CFR 430.32 — federal energy conservation standards (eCFR) — room AC CEER minimums from 2026-05-26; SEER2 regions; dehumidifier IEF; water heater UEF · checked October 2026
NOAA Climate Prediction Center — population-weighted state degree days — monthly normal heating and cooling degree days by state (base 65°F) · checked October 2026
EIA-861M sales and revenue by state — 2025 average household use and bill per state (U.S. 878 kWh, $151.88 a month) · checked October 2026
EIA Electric Power Monthly technical notes — average price = revenue ÷ sales, including fixed customer charges, fuel adjustments and surcharges · checked October 2026

Short answer

A 12,000 BTU mini-split draws about 0.53 kW and costs $0.10 an hour running — about $71.77 over a 750-hour U.S.-average cooling year at 18.19¢/kWh.

Power = capacity ÷ efficiency: 12,000 BTU/h ÷ SEER2 22.81 = 526 W.

DOE rates room air conditioners on 750 full-load hours a year; spread by U.S. cooling degree days that peaks in July at about 6.4 hours a day — $18.95 that month.

Inverter mini-splits run at part speed most of the time, which is why their seasonal rating is so much higher than their full-speed EER2 (12.79).

In a hot state the same unit runs far more: Texas has 2.2× the U.S. cooling degree days, Florida 2.8×. Pick your state in the calculator.

Adjust it to your exact job

Your air conditioner

Type

Size

SEER2

ENERGY STAR mini-splits around 12,000 BTU average SEER2 22.81.

How much it runs

Run time

750 full-load hours a year: DOE's 750-hour national basis × 1,216 cooling degree days in the U.S. ÷ 1,216 U.S.

Electricity rate

Where you live

Price per kWh

EIA's state average: total residential revenue ÷ kWh sold, so delivery and fixed monthly charges are spread over every kWh.

12,000 BTU mini-split in July

$18.95a month

$71.77 a year (395 kWh) · $0.10 per hour running

At 18.19¢/kWh — U.S. average, Jan–Aug 2026 (EIA).

Per hour running: $0.100.53 kW average draw
Busiest month (Jul): 6.4 hfull-load hours a day
Per year: $71.77750 full-load hours
Capacity: 12,000BTU/hSEER2 22.81

Estimated monthly cost in the U.S.

Same use, other efficiency

Yearly cost by efficiency rating
Efficiency	Per year	vs yours
ENERGY STAR average (SEER2 22.81)	$71.77	—
SEER2 18	$90.95	+$19.18

How to cut it

Raise the thermostat a few degrees and run a ceiling fan instead — an ENERGY STAR fan uses about 35 W on high.
Change the filter and keep the outdoor coil clear of leaves and grass so the system moves heat as rated.
Close blinds on sun-facing windows in the afternoon, when cooling hours peak.

Energy budget

395 kWh 12,000 BTU mini-split — cooling season electricity750 full-load hours at 18.19¢/kWh$71.77

Estimated total$71.77

Size

Efficiency

Watts

Per hour

Per year

9,000 BTU

SEER2 22.81

395

$0.07

$53.83

12,000 BTU

SEER2 22.81

526

$0.10

$71.77

18,000 BTU

SEER2 22.81

789

$0.14

$108

24,000 BTU

SEER2 22.81

1,052

$0.19

$144

How this was worked out

12,000 BTU/h ÷ 22.81 = 526 W = 0.526 kW. × 18.19¢ = $0.10 per running hour. × 750 hours = $71.77 a year.

Prices are EIA's U.S. average residential price for Jan–Aug 2026. Efficiency figures are ENERGY STAR certified averages (window units) or the federal minimum shown.

The full method, material data and tips are on the main air conditioner cost calculator page.