Tachymeter: How to Use One for Accurate, Speed-Based Calculations | Lapizta Racing Watches and Luxury Sports Watches

Tachymeter: How to Use One for Accurate, Speed-Based Calculations

Tachymeter: How to Use One for Accurate, Speed-Based Calculations

Just like in the movies, two cars rev up their engines awaiting the checkered flag to come down and signal the start of the race. At the end of the motor path, someone holds up his chronograph knowing that the press of the tachymeter on the bezel of his watch will measure the speed of the cars over the distance. It is not the drivers in the car that have the power; it is the timekeeper, and ultimately, the tachymeter scale.


Luxury sports watches may have rotating or fixed bezels, according to preference. The real star, however, is the tachymeter. A tachymeter computes constant speed based on time of travel. The measure can be found on the rim of some analog watches with pronounced spacings on the dial. These spacings measure the speed over distance with a formula of

Where T stands for the measured time in seconds of constant speed over distance over one and multiplied by 3600 seconds divided by one full hour or multiply the number by 3600 seconds and then divide by one full hour.

Most chronographs feature tachymeters, yet many wearers do not understand how to utilize them to calculate time. If they do know about this function, they might be confused since the scales do not correlate to seconds, minutes, and hours. The style of the watch may also be a source of confusion; luxury sports watches come with rotating or fixed bezels, according to preference, but the rotation is of little consequence. It’s the spacing of the dial that’s key to making the calculation

A bezel that rotates is not the same as a tachymeter. A rotating bezel measures in increments from 0-60, whereas the tachymeter charts in increments of 60 to 400 or 500. One begins where the former ends.

 Americans use the Imperial system and will measure using miles. Europeans use the metric system, but as long as the units used maintain the same distance throughout your calculations the time will bypass cultural preferences.


Let’s say the person timing the race presses the tachymeter to indicate the race has begun and sees the tabulating hand pointing to 11 o’clock on the dial.

We’ll say the hand is pointing to 11 o’clock, so 55 seconds have passed since starting. The number on the tachymeter bezel adjacent to 11 o’clock is 65. This means the car being tracked is traveling at 65 miles per hour.

You can use this process to calculate the speed of anything traveling faster than 60 units per hour. Measuring slower speeds will require a little mental math; decreasing the unit of measurement can do it.

An example of using the tachymeter can include divers who use their divers watches to time how long it takes to reach a sunken ship or to return to the water’s surface.


While it is true that digital watches are tremendously popular, there is something to the time-honored tradition of a timepiece with a tachymeter scale. It gifts the wearer with self-reliance, allowing you to calculate what you need without leaning on technology or keeping close to an electrical outlet to recharge

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