How Much Does It Cost to Run a CPAP Machine?
Short answer: about $0.055 a day and $1.66 a month, or $0.007 for each hour it runs at full power, at the 2025 US average electricity rate. That is for a 40 W cpap machine running 8 hours a day with a 100% duty cycle. Change the state and hours below for your own number.
Updated Nov 8, 2026
Quick answer
Quick answer, US average (17.3 c/kWh)
About $1.66 a month
The same use costs $1.13 a month in North Dakota and $3.90 in Hawaii.
- Per hour
- $0.007
- at 40 W
- Per day
- $0.055
- 8 h, 0.32 kWh
- Per month
- $1.66
- 30 days
- Per year
- $20.21
- 365 days at the same use
Your state, your hours
Per hour
$0.007
Per day
$0.055
Per month
$1.66
Per year
$20.21
CPAP Machine at 40 W, 8 h a day, 30 days a month, 100% duty cycle: 9.6 kWh a month. Using the 2025 US average of 17.3 cents/kWh.
Want to change the watts or duty cycle too? Open the full calculator.
What decides the cost of running a cpap machine
A CPAP machine is a small, quiet blower that holds a steady air pressure in the mask. The blower itself draws very little, about 20 to 60 W depending on the pressure setting and the model. A machine set to a low pressure of 6 to 8 cm H2O sits near the bottom of that range, and one set to 15 or above sits near the top. The default here is 40 W for 8 hours, 0.32 kWh a night, about 5.5 cents at the national average rate.
The heated humidifier is what changes the number. A heated water chamber and a heated tube can triple the draw, and this site uses 110 W at an 80 percent duty cycle for a CPAP with its humidifier on, about 0.7 kWh a night or 12 cents. The power brick that comes with the machine is often rated 65 to 90 W or more. That rating is the most the machine can ever pull, with the humidifier and heated tube at full, not what it uses on a normal night.
Over a year a CPAP without humidification uses about 117 kWh, roughly $20. With the heated humidifier on every night it is closer to $44. Either way it is one of the smallest loads in a bedroom, and there is no reason to turn the humidifier down to save money at home if it helps you use the machine.
The place where the watts really matter is on battery. In an outage, or camping, a CPAP running at 40 W uses about 320 Wh at the mask over 8 hours. Running it through a power station's AC inverter adds 10 to 20 percent in losses, so plan on about 375 Wh from the battery. Turning off the humidifier and heated tube for the night, and using the maker's DC cable if one exists, can roughly halve what you need. With the humidifier on, the same night takes 700 Wh or more.
Always follow your prescriber's guidance on settings. This page covers electricity only.
How to cut it
- On battery, turn off the heated humidifier and heated tube; they can triple the draw.
- Use the maker's DC power cord with a power station's 12 V port to skip inverter losses.
- Fill the humidifier chamber with room-temperature distilled water so the heater does less work warming it.
- Keep the filter clean so the blower does not have to work harder to hold pressure.
CPAP Machine cost by state
Monthly cost for 40 W, 8 h a day, 100% duty cycle, 30 days, sorted cheapest to most expensive. Pick your state above to highlight it.
| Rank | State | Cents/kWh | Per month |
|---|---|---|---|
| 1 | North Dakota | 11.81 | $1.13 |
| 2 | Idaho | 11.82 | $1.13 |
| 3 | Nebraska | 12.34 | $1.18 |
| 4 | Louisiana | 12.57 | $1.21 |
| 5 | Arkansas | 12.84 | $1.23 |
| 6 | Montana | 12.98 | $1.25 |
| 7 | Utah | 13.07 | $1.25 |
| 8 | Washington | 13.11 | $1.26 |
| 9 | Oklahoma | 13.12 | $1.26 |
| 10 | Nevada | 13.15 | $1.26 |
| 11 | Tennessee | 13.18 | $1.27 |
| 12 | Kentucky | 13.24 | $1.27 |
| 13 | South Dakota | 13.38 | $1.28 |
| 14 | Wyoming | 13.38 | $1.28 |
| 15 | Missouri | 13.49 | $1.30 |
| 16 | Iowa | 13.72 | $1.32 |
| 17 | North Carolina | 14.02 | $1.35 |
| 18 | Mississippi | 14.03 | $1.35 |
| 19 | Kansas | 14.56 | $1.40 |
| 20 | Georgia | 14.73 | $1.41 |
| 21 | South Carolina | 14.96 | $1.44 |
| 22 | New Mexico | 15.08 | $1.45 |
| 23 | Florida | 15.24 | $1.46 |
| 24 | Virginia | 15.28 | $1.47 |
| 25 | Arizona | 15.32 | $1.47 |
| 26 | Oregon | 15.37 | $1.48 |
| 27 | West Virginia | 15.41 | $1.48 |
| 28 | Texas | 15.47 | $1.49 |
| 29 | Minnesota | 15.82 | $1.52 |
| 30 | Colorado | 15.85 | $1.52 |
| 31 | Alabama | 16.10 | $1.55 |
| 32 | Indiana | 16.23 | $1.56 |
| 33 | Ohio | 16.96 | $1.63 |
| 34 | Delaware | 17.13 | $1.64 |
| 35 | Illinois | 17.69 | $1.70 |
| 36 | Wisconsin | 18.16 | $1.74 |
| 37 | Pennsylvania | 19.30 | $1.85 |
| 38 | Maryland | 19.48 | $1.87 |
| 39 | Michigan | 20.01 | $1.92 |
| 40 | District of Columbia | 21.94 | $2.11 |
| 41 | New Jersey | 22.63 | $2.17 |
| 42 | Vermont | 22.92 | $2.20 |
| 43 | New Hampshire | 24.56 | $2.36 |
| 44 | Alaska | 26.09 | $2.50 |
| 45 | New York | 26.39 | $2.53 |
| 46 | Maine | 27.78 | $2.67 |
| 47 | Connecticut | 29.38 | $2.82 |
| 48 | Rhode Island | 29.46 | $2.83 |
| 49 | Massachusetts | 30.48 | $2.93 |
| 50 | California | 32.54 | $3.12 |
| 51 | Hawaii | 40.59 | $3.90 |
Rates: U.S. Energy Information Administration, Form EIA-861, annual average residential price, 2025 (eia.gov). Full list on the electricity rates by state page.
Measure it instead of estimating
P3 Kill A Watt P4400 Electricity Usage Monitor
Plugs in between the wall and any 120 V appliance and shows watts and accumulated kWh. The cheapest way to replace the estimate on this page with your own number.
Under $100, live price on Amazon
Check price on AmazonPaid link. We earn a commission at no cost to you.
Each card says whether its link is paid. We earn a commission if you buy through Amazon.
Frequently asked questions
How much does it cost to run a CPAP machine per night?+
About 5.5 cents a night without the humidifier. A 40 W machine for 8 hours uses 0.04 x 8 = 0.32 kWh, and 0.32 x $0.173 is $0.055. With the heated humidifier on, about 12 cents.
How much does it cost to run a CPAP per month?+
About $1.66 a month without humidification: 0.32 kWh x 30 = 9.6 kWh, and 9.6 x $0.173 is $1.66. With the heated humidifier at 110 W and an 80 percent duty cycle it is about $3.65.
How much does it cost to run a CPAP per year?+
About $20 a year without the humidifier: 0.32 kWh x 365 = 117 kWh, and 116.8 x $0.173 is $20.21. With the heated humidifier every night it is about 257 kWh, roughly $44.
How many watts does a CPAP machine use?+
About 20 to 60 W without the humidifier, depending on the pressure setting. With a heated humidifier and heated tube it can draw 80 to 130 W. The power brick's rating is the maximum, not the typical draw.
Does a CPAP machine use a lot of electricity?+
No. Without the humidifier it uses about 117 kWh a year, about the same as a ceiling fan run a few hours a night. Even with the humidifier on it is about $44 a year at the national average rate.
How much does a CPAP cost per hour to run?+
Under 1 cent an hour. At 40 W it uses 0.04 kWh an hour, and 0.04 x $0.173 is $0.007. With the heated humidifier at about 88 W average it is about 1.5 cents an hour.
How much does the CPAP humidifier add to the cost?+
About 6.6 cents a night, or $2 a month. The default CPAP alone uses 0.32 kWh a night; with the heated humidifier it uses about 0.7 kWh (110 W x 8 hours x 0.8), so the humidifier adds about 0.38 kWh.
How long will a power station run a CPAP?+
About 2 to 2.5 nights on a 1 kWh power station without the humidifier, since one night needs about 320 Wh at the mask and about 375 Wh from the battery through the inverter. With the humidifier on, plan on about one night.
Can I run a CPAP on a generator?+
Yes. A CPAP draws so little that any generator runs it, but use an inverter generator, which produces clean power suited to the machine's electronics, and keep the generator outdoors, well away from windows, because of carbon monoxide.
How can I lower the power a CPAP uses on battery?+
Turn off the heated humidifier and heated tube, use a DC cord instead of the AC inverter, and keep the filter clean. Together those can cut a night from 700 Wh or more down to roughly 300 to 375 Wh.
Marcus Reed
Founder and Editor, CrunchYourDollars
Marcus Reed builds the sizing tools on CrunchYourDollars. He is a software engineer with a long-running PC hardware and power supply habit, which is where the watts, watt-hours and surge math on this site comes from. Product specs are pulled from manufacturer data sheets, electricity rates from the U.S. Energy Information Administration, and water chemistry rules from the Water Quality Association. He is not a licensed electrician or plumber: the tools show the math and the matching models so you can make the call, and anything involving your electrical panel should be checked by a licensed pro.
More about CrunchYourDollars and how we researchGet notified when we add tools
An occasional email when a new sizing tool goes live or the product database is refreshed. No spam, unsubscribe anytime.