mph means miles per hour. It tells you how fast something is going — a car, a train, or the wind. “70 mph” on a US highway sign is a speed limit. Britain uses mph on the roads too. Most other countries, including Taiwan, use kilometres per hour (km/h or kph). Roughly, 60 mph is about 97 km/h, so the numbers feel bigger in km/h. People say it as letters, em-pee-aitch, or they just say “miles an hour.” It is the normal unit-word, not slang and not fancy. Weather reports in the US also give wind in mph.

英里每小時（時速；台灣用公里每小時）