What Size Generator Do You Need for a CPAP Machine or Oxygen Concentrator?
A CPAP uses only 30–90 watts, so any generator runs it, but it needs clean, stable power. An oxygen concentrator needs more and runs continuously.
| Appliance | Running / starting W | On its own | With fridge, lights and Wi-Fi |
|---|---|---|---|
| CPAP machine | 60 / 60 | 2,000-watt 10 kW standby | 2,000-watt 10 kW standby |
| Oxygen concentrator | 350 / 700 | 2,000-watt 10 kW standby | 3,000-watt 10 kW standby |
Smallest portable (by starting watts) and smallest standby generator on natural gas, keeping about 20% headroom.
Tips
- Use an inverter generator or a standby unit; cheap open-frame generators can produce power that confuses sensitive electronics.
- Keep a battery pack made for your device so it rides through the gap until the generator starts.
- Tell your utility company if someone at home depends on medical equipment; many have priority restoration lists.
See also the appliance wattage chart and what each generator size can run.