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How many watts does a mini split use?

A mini split uses 500–2,500 watts while running, which is 2.1–10.4 amps at 240 V.

Mini split watts, amps and circuit

Typical power use of a mini split
Running watts500–2,500 W
Voltage240 V
Running amps2.1–10.4 A
Circuitdedicated 240 V circuit, breaker size from the nameplate

Also called: ductless mini split, mini split ac, ductless heat pump.

Mini split watts by size and type

Running and starting watts of mini split types
Size or typeRunning watts, WVolts, VAmps, AStarting watts, W
Mini split500–2,5002402.1–10.4—
9,000 BTU500–9002402.1–3.8—
12,000 BTU700–1,2002402.9–5—
18,000 BTU1,100–1,8002404.6–7.5—
24,000 BTU1,500–2,5002406.3–10.4—
36,000 BTU2,500–3,80024010.4–15.8—
02,0004,000Watts, WSize or typeMini splitMini split, Running watts: 500–2,500500–2,5009,000 BTU9,000 BTU, Running watts: 500–900500–90012,000 BTU12,000 BTU, Running watts: 700–1,200700–1,20018,000 BTU18,000 BTU, Running watts: 1,100–1,8001,100–1,80024,000 BTU24,000 BTU, Running watts: 1,500–2,5001,500–2,50036,000 BTU36,000 BTU, Running watts: 2,500–3,8002,500–3,80001,0002,0003,0004,000Watts, WSize or typeMini splitMini split, Running watts: 500–2,500500–2,5009,000 BTU9,000 BTU, Running watts: 500–900500–90012,000 BTU12,000 BTU, Running watts: 700–1,200700–1,20018,000 BTU18,000 BTU, Running watts: 1,100–1,8001,100–1,80024,000 BTU24,000 BTU, Running watts: 1,500–2,5001,500–2,50036,000 BTU36,000 BTU, Running watts: 2,500–3,8002,500–3,800
Watts of mini split types. The lighter part of a bar is the upper end of the typical range.

What size generator runs a mini split?

A mini split needs a generator that supplies at least 2,500 running watts. Starting a mini split takes a short surge of several times its running watts, and the surge is not listed here: size the generator from the locked-rotor amps (LRA) on the nameplate or the maker's generator guidance, not from the running watts. The generator must have a 240 V outlet or be connected through a transfer switch or interlock.

What it costs to run a mini split

Running a mini split at 1,500 W, the middle of its 500–2,500 W range, for one hour a day uses 547.5 kWh a year. That costs about $99 a year at $0.18 per kWh, the US average residential price for August 2026.

W
h
$/kWh

Your bill's total ÷ kWh used. 0.18 is the US residential average.

Result
$8.21 / month
Per day
$0.27
Per year
$99
Energy per day
1.5 kWh
Energy per month
45.6 kWh

How it is calculated

  1. kWh per day = 1,500 W × 1 h ÷ 1,000 = 1.5
  2. Per month = 1.5 kWh × 30.4 days × $0.18 = $8.21

What affects mini split power use

Mini splits use inverter compressors that ramp speed up and down, so they rarely run at full power and start without a large surge. The figures are the range at full output for each size. Small models are made for 120 V; most are 240 V, and larger sizes need a bigger breaker as listed on the outdoor unit nameplate.

How the amps are calculated

Amps = watts ÷ volts. For 2,500 W at 240 V that is 10.4 A. The 500–2,500 W range covers typical models; the nameplate on a mini split gives the exact figure.

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