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How many watts does a CPAP machine use?

A typical CPAP machine uses 6–104 watts when running and draws 0.05–0.87 amps at 120 volts.

CPAP machine watts, amps and circuit

Typical power use of a CPAP machine
Running watts6–104 W
Voltage120 V
Running amps0.05–0.87 A
Circuitstandard 120 V outlet

Also called: cpap, apap, bipap.

CPAP machine watts by size and type

Running and starting watts of CPAP machine types
Size or typeRunning watts, WVolts, VAmps, AStarting watts, W
CPAP machine6–1041200.05–0.87—
Without heated humidifier6–271200.05–0.23—
With heated humidifier53–1041200.44–0.87—
050100150Watts, WSize or typeCPAP machineCPAP machine, Running watts: 6.3–1046.3–104Without heatedhumidifierWithout heated humidifier, Running watts: 6.3–276.3–27With heatedhumidifierWith heated humidifier, Running watts: 53–10453–1040255075100125Watts, WSize or typeCPAP machineCPAP machine, Running watts: 6.3–1046.3–104Without heated humidifierWithout heated humidifier, Running watts: 6.3–276.3–27With heated humidifierWith heated humidifier, Running watts: 53–10453–104
Watts of CPAP machine types. The lighter part of a bar is the upper end of the typical range.

What size generator runs a CPAP machine?

A CPAP machine needs a generator that supplies at least 104 running watts. A 2,000 W generator covers it with its running rating alone; add the watts of anything else you run at the same time.

How long a portable power station runs a CPAP machine

Runtime of a CPAP machine on a portable power station, at 85% inverter efficiency
Battery capacity, WhAt 104 W, hAt 6.3 W, h
5004.167.5
1,0008.2134.9
2,00016.3269.8
3,60029.4485.7

A 500 Wh portable power station runs a CPAP machine drawing 104 W for about 4.1 hours at 85% inverter efficiency. Runtime = capacity × 85% ÷ watts; the 85% efficiency is an assumption. The power station's AC output must be at least 104 W.

What it costs to run a CPAP machine

Running a CPAP machine at 55 W, the middle of its 6–104 W range, for one hour a day uses 20.1 kWh a year. That costs about $3.61 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
$0.30 / month
Per day
$0.01
Per year
$3.61
Energy per day
0.06 kWh
Energy per month
1.7 kWh

How it is calculated

  1. kWh per day = 55 W × 1 h ÷ 1,000 = 0.055
  2. Per month = 0.055 kWh × 30.4 days × $0.18 = $0.30

What affects CPAP machine power use

The blower motor alone draws little; the heated humidifier and heated tube use most of the power. Higher pressure settings raise the draw slightly. For a battery or power station during an outage, turning off the humidifier stretches run time the most.

How the amps are calculated

Amps = watts ÷ volts. For 104 W at 120 V that is 0.87 A. The 6–104 W range covers typical models; the nameplate on a CPAP machine gives the exact figure.

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