HOW DO YOU MAKE A SPEEDOMETER FOR ARDUINO

Hi, I wanted to make a speedometer with the Arduino and display it on an LCD
I am inquiring on how to do this
Please help,
Thank you

If you Google 'Arduino Speedometer' you get 1/4 million hits.

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You will need to buy an appropriate sensor and connect it to something that moves.

What do you want to measure the speed of? Don't you think that's a pretty critical detail?