There are approximately 40 countries that use 60 Hz while the rest typically run on 50 Hz current. Single-phase power is primarily for residential use (such as homeowners and what you would find in a hotel) while 3-phase electric power provides more stable, heavy-duty power for most industrial applications like manufacturing plants, commercial facilities, data centers, telecom towers, hospitals, food processing, and utility power plants.

Some applications use specialized higher voltages (such as 4160 V or 13,400 V) but these are on a more unique basis and typically involve transformers so those are not included. When considering a backup power generator, keep in mind that the frequency can often be changed by an accomplished power generation technician or electrical contractor but you do typically see a performance loss on most generator sets when you convert from 60 hertz to 50 hertz. This is mainly because you have to slow the engine RPM down and make adjustments so the overall kW or kVA output will be lower. The opposite is also true – you can sometimes gain kW when you convert from 50 Hz to 60 Hz because you speed the engine RPM up. The number of wires and plugs used varies greatly by region since each country is evolving their electrical grids at a different rate and over time so these are only provided as a good starting point and general guide.

Why Do Some Countries Use 50 Hz and Others 60 Hz?

The split between 50 Hz and 60 Hz power systems across the globe is a quirky relic of early electrical engineering, rooted in competing industrial ambitions and practical choices made over a century ago. It’s not just a technical detail—it’s a story of innovation, rivalry, and legacy.

Back in the late 1800s, electricity was the new frontier. Europe, led by German engineers at companies like AEG, leaned toward 50 Hz. Why? It was a practical sweet spot. Early generators, tied to steam engines or water turbines, operated at speeds that naturally aligned with 50 cycles per second. This frequency worked well for bulky transformers and motors of the era, balancing efficiency with the limits of iron-core technology. Plus, 50 Hz flickered less noticeably in early arc lamps, a big deal for lighting up factories and streets.

Across the Atlantic, American engineers, notably at Westinghouse, championed 60 Hz. The choice wasn’t random—60 Hz allowed slightly smaller, lighter transformers, which cut costs for sprawling U.S. power grids. It also synced nicely with the 60-second clock, simplifying some electrical calculations. Westinghouse’s team, backed by Nikola Tesla’s AC system, locked in 60 Hz as the U.S. standard by the 1890s, especially after high-profile projects like the Niagara Falls power plant.

So why the global divide? Colonial and industrial influence. European countries spread 50 Hz to their colonies—think India, Australia, and much of Africa. Meanwhile, the U.S. and its allies, like Japan and parts of South America, adopted 60 Hz. Some nations, like Japan, even ended up with both due to regional utility differences! Over time, these standards calcified. Switching frequencies now would mean rewiring entire grids—a costly, chaotic endeavor.

This 50/60 Hz split fascinates because it shows how early tech decisions, driven by practical needs and corporate battles, still shape our world. Next time you plug in a generator, you’re tapping into a century-old tug-of-war between engineering giants.

Still have questions or looking for more information?

Generator Source specializes in low-hour, used, new, and surplus generator sets. We have a wide variety of generator sizes and models to fit any project. We are not a broker, we own what we sell.
Call us today (877-866-6895) or click Contact Us to be connected with one of our experienced sales reps. 
We have 350+ generators in stock and ready to ship!

Schedule Service

Browse Inventory

Contact Us