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PLFree CPAP planning tool
How much electricity does your CPAP use?
Estimate the running cost of your own setup using average wall power, daily use and your electricity price.
Your power and electricity rate
Enter measured or estimated values for your setup. All running hours use the same average power and electricity rate.
Calculations stay in this tab. Inputs are not saved or sent by this tool; download a report before leaving.
Your electricity estimate
Enter your values, then calculate.
Inputs changed. Calculate again to update your estimate.
Check the highlighted inputs and calculate again.
Estimate ready. Values are rounded for display; calculations use unrounded inputs.
Cost for your planning period
USD
kWh over days- Daily energy
- kWh
- Daily running energy
- kWh
- Daily standby energy
- kWh
- Daily cost
- USD
- Annual energy (365 days)
- kWh
- Annual cost (365 days)
- USD
Assumes the same setup and hours every day. Excludes fixed account charges, tiered or time-of-use pricing, battery charging losses and other equipment. It does not recommend changing your prescribed use or comfort settings.
Transparent arithmetic
How the estimate works
Daily standby kWh = average standby watts × (24 − hours) ÷ 1,000
Period cost = (running kWh + standby kWh) × days × price per kWh
Annual results use 365 identical days. Your selected planning period is independent of the annual estimate. Values are displayed to at most four decimal places; positive values below 0.0001 are shown as < 0.0001. Calculations use unrounded values.
A worked example
With 40 W average running power for 8 hours, 2 W standby for the other 16 hours, and a rate of 0.25 per kWh: daily energy is 0.352 kWh and daily cost is 0.088. A 30-day period uses 10.56 kWh and costs 2.64; 365 days use 128.48 kWh and cost 32.12, in your chosen currency.
Choose inputs that match your setup
Average watts, not maximum ratings
A mains energy meter can measure kWh over representative use. Average running watts = measured running kWh × 1,000 ÷ running hours. Include your usual humidifier and heated hose. Measure standby separately, or exclude it explicitly; a measurement covering the whole day already includes standby and must not be counted again.
Your own variable rate
Use the cost per kWh from your electricity plan in major currency units. A single flat rate cannot reproduce time-of-use or tiered bills. Fixed daily account charges are excluded because this tool estimates the incremental energy cost of your CPAP setup.
Questions about CPAP electricity costs
Does the calculator know my machine’s power use?
No. It works with any brand using values you enter. Power depends on your setup and use, so there is no preset device wattage or guaranteed cost. An adapter’s maximum output rating is not a measurement of average energy drawn at the wall.
Can I use my electricity bill’s cents-per-kWh rate?
Convert cents to major currency units first: 25 cents becomes 0.25. Choose a currency label for the report. The label does not change or convert the numbers, and the site’s shopping currency does not set your electricity tariff.
Should I change CPAP settings or hours to reduce the estimate?
This is a budgeting tool, not a treatment recommendation. Follow your prescribed use and discuss treatment or comfort settings with your care team. Enter your own duration rather than treating any example as a target.
Does this calculate battery runtime?
No. It estimates wall electricity. Battery capacity, conversion losses and equipment compatibility require a different calculation. Use the separate battery runtime estimator linked below.
Are my inputs saved?
No. This tool calculates in your browser without saving or uploading its inputs. Download the text report or print before leaving. Changing an input hides the previous estimate until you calculate again.