- Where and why is speed given in miles per hour?
- How do you convert miles to kilometers and vice versa?
- Travel safely in countries with miles
- Speedometer conversion in American cars
- Conclusion: Don’t go crazy with the conversion!
Where and why is speed given in miles per hour?
In English-speaking countries where the metric system is not mandatory, the speed is given in miles per hour or mph for short. For example in Great Britain or in the USA. This can be confusing for European drivers, for example when they suddenly read miles per hour instead of kilometers per hour as the speed limit on motorway signs.
The mile unit of measurement originally comes from the ancient Roman Empire. At that time, distances were measured in steps or double steps. The simple average step length was 74 centimeters. And one mile equaled about 1,481 meters, which in turn equaled a thousand double steps. Today, however, a mile is the equivalent of about 1,600 meters.
Meters and miles – why are there different units of measurement at all?
In the past, there were different units of measurement such as lengths and weights, which were to be standardized with the metric system of units, or metric system for short. The metric system uses the meter as the basic unit of measurement to indicate the length of a distance.
In the USA, for example, the Anglo-American system of measurement is still used, with measurements such as feet, inches and miles.
How do you convert miles to kilometers and vice versa?
Converting a mile to a kilometer is easy to do.
One mile equals 1.609344 kilometers. Accordingly, 1 mph is equivalent to 1.609344 km/h (rounded down to 1.61 km/h).
So if I want to convert miles to kilometers, I can simply multiply the miles by a rounded factor of 1.6. 100 miles per hour is 160 kilometers per hour.
Conversely, one kilometer equals 0.621371 miles (0.62 miles rounded down). So I can easily convert kilometers to miles by multiplying the kilometers by 0.62. So 100 kilometers per hour corresponds to about 62 miles per hour.
|miles per hour (mph)||Kilometers per hour (km/h), rounded|
|kilometers per hour (km/h)||Miles per hour (mph), rounded|
Travel safely in countries with miles
Anyone who has ever traveled by car in the USA certainly knows the feeling of free driving on the seemingly endless highways. However, the speed limits must be observed. Depending on the state, violations are punished with very high fines, even for tourists.
If a rental car is booked on site, there is usually no problem due to the international speed information. American vehicles almost always have both units of measurement on the speedometer – mph in large numbers in the outer circle of the speedometer display and km/h in small numbers in the inner circle.
Speedometer conversion in American cars
However, anyone who buys an American classic car could also encounter the problem of only being able to read miles on the speedometer. Old American cars in particular often only have miles on the speedometer.
Can I change the speedometer from mph to kmh on a US vehicle?
The easiest and cheapest solution to being able to read the km/h reading on a speedometer that only shows miles is to buy special stickers. These are simply glued to the speedometer glass. Especially with vintage cars, however, a lot of value is placed on the optics, which is why this is certainly not the most beautiful solution for many. It should also be noted that the speed given on the km/h number is not quite exact.
Another possibility is the conversion of the speedometer. However, this is usually complex and cost-intensive. In order to have correct measured values, not only the dial and the speedometer glass have to be replaced, but the entire system has to be converted. In addition, it is not so easy to find a spare part that looks as true to the original as possible.
Conclusion: Don’t go crazy with the conversion!
The best way to drive is to simply ignore the km/h scale. Over time, you will automatically get a feel for the number of miles per hour. However, if you are driving a car that only measures speed in km/h, it is advisable to roughly memorize the conversion from mph to km/h.