We've all seen tachymeters on watches that start at 60mph above 12:00 (logically).

In my entire life (71 years), I have only seen one that measures below 60mph.

A friend had one back in the 1960s that went down to 50mph, somewhere around 1:00-2:00 (IIRC).

Being able to gauge 500mph over a measured mile may come in handy at sometime, but speeds a little lower than 60mph might be a little more "real world" practical for some folks.

Anybody ever see a watch with a tachymeter that measures below 60mph?

John?

For times over 60 seconds over a measured one-mile distance, the basic equation is:

3600/(Total seconds) = Speed in MPH

For the metric-minded out there, if you use a measured one-kilometer distance you get the results in KPH.

There is a method for using a standard tachymeter for timing slower things but the equation above is by far the easiest.

Hope this helps.