Depending on which country you are living in, the speed is measured either in kilometers or miles per hour. This is the same logic when buying a used car from overseas. If you are trying to import or buy a car directly from Japan, for instance, you will notice that the odometer is in kmh (kilometers per hour). But if you are from the USA, you would definitely be more familiar with mph (miles per hour). Currently, only about 9% of the world uses miles per hour, including the USA. What about other countries?

Japan is one of the 81% of the countries which use kmh sometimes referred to as kph, along with Australia, UAE, and Kenya. These are the units used for displaying speed limits on roads and highways as well as when you buy a car. So you might need to keep in mind if you plan on driving in other countries or in a car that might use a different metric system than your own.

Speed Limits Around the World

If you are driving in the USA, the typical speed limit on highways would be around 65 to 75 mph. On the other hand, Japanese highways would usually be around 80 to 100 kmh. So how much would that be in mph? 

Roughly 50 to 62 mph. Meaning that the speed limit on highways in Japan is slightly lower than in the USA. Poland also uses kmh and the speed limit for their expressways goes up to 120 kmh (approx. 75mph) but on their motorways, it becomes 140 kmh (about 87 mph)! But don’t let this fool you, driving regulations in Poland are known to be very strict and traffic laws are heavily enforced too to ensure safety on the roads.

Countries that Use KMH and MPH

To convert kmh to mph, you can use the following formula: 

mph = kmh x 0.621371

For example, if you want to convert 300 kmh to mph, that would be approximately 186.411 mph.

Pop quiz! What is the following kmh to mph on the odometer of these used cars?

Converting Your Speedometer From KMH to MPH

Cars made in Europe and Japan are designed to have a speedometer using the kmh metric system. But cars made in the UK would be in mph. Therefore, you would need to find a way to read or constantly do mental math in your head for conversions. But if you aren’t good at mental math like us, well here are some ways you can use to convert kmh to mph.

Using an Inline Speedo Converter

This is where you install an aftermarket converter to accurately change your speed readout to mph in real time. But the choices might be limited to either cord type or a chip. Chip converters are placed on the harness of your current speedometer and adjust the signal without having to change any equipment. Cord types, on the other hand, replace the entire speedometer harness. So keep in mind that not all converters are suitable for your vehicle.

Changing the Dials

This is done by changing the entire dial to reflect mph. However, the procedure is delicate and should only be done by an expert as it invoices the cluster from the dashboard. This type of technical work varies depending on the car and the level of difficulty since dials could be set up in different positions too. 

But remember, it is important to make sure that the view of your speedometer is not obscured after the change as it is illegal in many countries and highly dangerous!

If you plan on getting a used car from Japan, always make sure to know your metrics and how to convert it. It’s important to abide by the road traffic laws and keep yourself safe. Here is a simple KMH to MPH conversion table for the common speed limits around the world.

Updated: This article was updated on October 28, 2024, for accuracy and relevancy. Please feel free to leave us feedback or comment below for questions!