How many countries still use miles per hour?

Miles per Hour: A Measure of Speed Still Used in a Select Few Nations

In the realm of measuring speed, the vast majority of countries have adopted the metric system, utilizing kilometers per hour (km/h) as their standard unit. However, two notable exceptions to this global trend remain: the United States and the United Kingdom.

These two nations continue to employ the miles per hour (mph) system, a legacy of their historical use of the imperial system of measurement. As a result, the speed limits on roads and highways in the US and UK are expressed in miles per hour, and their vehicles’ speedometers are calibrated accordingly.

The continued use of mph in the United States and the United Kingdom is rooted in a combination of cultural inertia, tradition, and the fact that their infrastructure has been built around this system for decades. Converting to the metric system would require a significant investment in updating signage, recalibrating vehicles, and educating the public.

It is worth noting that even within these two countries, there are some signs of gradual transition to the metric system. The UK, for instance, uses kilometers for measuring distances on road signs, while the US military and scientific communities also utilize the metric system.

While the use of mph in the US and UK may appear anachronistic in the era of global standardization, it serves as a testament to the enduring influence of historical practices and the complexity of transitioning to new measurement systems. It remains to be seen whether these two nations will eventually join the rest of the world in adopting km/h as their universal speed unit.