Inverter vs. conventional generators
The biggest practical difference isn't power output — it's power quality, and it decides whether your electronics are safe.
How they differ
A conventional generator runs its engine at a constant speed (3,600 rpm in the US) to produce 60 Hz AC directly. An inverter generator produces AC, rectifies it to DC, then electronically inverts it back to a clean, regulated AC sine wave. That extra conversion step is what lets it hold voltage and frequency steady.
Power quality: THD
Power quality is measured as total harmonic distortion (THD). Utility grid power sits below about 5% THD, often under 3%. Inverter generators typically produce output below 3% THD — comparable to grid power — while conventional generators produce higher, more variable distortion. High-THD power can cause sensitive electronics (laptops, phones, smart TVs, medical devices, anything with a microprocessor) to overheat, malfunction, or fail prematurely.
| Factor | Inverter | Conventional |
|---|---|---|
| Power quality (THD) | <3% | higher / variable |
| Sensitive electronics | Safe | Risky without conditioning |
| Noise | Low (conversation level) | Higher |
| Fuel efficiency | Better (variable engine speed) | Constant speed |
| Max power / cost | Lower power, higher $/W | Higher power, lower $/W |
Which should you choose?
Choose an inverter generator if you'll run electronics, want quiet operation, or need clean power for medical gear. Choose a conventional generator if you mainly run motors, pumps, and power tools where power quality matters less and you want the most watts per dollar. Many homeowners size by load with our load sizer, then pick the type by what they're powering.
Sources
- U.S. CPSC — generator safety & power quality guidance
- Anker / industry THD reference (3–5% inverter typical)
External figures attributed to the bodies above; wattage estimates on this site are typical planning values to verify against your equipment.