What Is The Tachymeter On A Watch?

In the realm of intricate timepieces, there’s a feature that stands out for its unique ability to turn a stylish watch into a functional tool—the tachymeter.

This component, which may appear as a mere aesthetic element to the untrained eye, holds the power to measure speed based on travel time or measure distance based on speed.

A solid understanding of the tachymeter can amplify the appreciation for your wristwatch, taking it beyond a simple time-telling device and turning it into a piece of sophisticated machinery.

Tachymeters, typically found on the bezels of chronograph watches, provide a window into the precision engineering that forms the backbone of watchmaking. They embody the blend of practicality and luxury that quality watches are known for.

Exploring the depths of what a tachymeter brings to a timepiece opens up a new perspective on what makes a great watch tick.

Delving into the world of tachymeters, we’re set to unravel the mystery behind this intriguing watch component. Through this journey, you will gain a comprehensive understanding of the tachymeter, its workings, its essential parts, and how to use it.

We’ll also touch on the types of watches that feature tachymeters, discuss their pros and cons, clear common misconceptions, and finally answer some frequently asked questions.

What is a Tachymeter?

Embedded in the world of horology is the tachymeter—a scale inscribed around the rim of a watch used in conjunction with the chronograph.

It originates from the Greek words ‘taches’, meaning ‘swift’, and ‘metron’, meaning ‘measure’. The concept of the tachymeter surfaced during the late 19th century, born from the desire to extend a watch’s functionality beyond merely telling the time.

In essence, a tachymeter measures speed based on time traveled over a fixed distance, or alternatively, it can calculate distance based on speed. This feature transformed watches into invaluable tools for pilots, racers, and anyone in need of measuring speed or distance.

How Does a Tachymeter Work?

The fundamental operation of a tachymeter resides in the relationship between time and speed. With the scale of the tachymeter typically based on one hour, the user can calculate speed or distance by timing an event or activity using the chronograph function of the watch.

For instance, if you want to calculate the speed of a car, start the chronograph at a set point and stop it after exactly one mile or kilometer.

The second hand’s position on the tachymeter scale reveals the car’s speed. On the other hand, if you know the speed and want to determine the distance traveled, you can use the tachymeter scale in conjunction with the known speed to find out the distance covered in one hour.

What Are the Parts of a Tachymeter?

A tachymeter comprises a numbered scale usually engraved or printed on the bezel of the watch, or sometimes placed on the outer edge of the watch dial.

The scale typically starts at 60 (at the top center position, coinciding with the minute and hour hand at zero) and goes down to 400 or 500, depending on the model of the watch. The numbers represent the units of speed — miles per hour or kilometers per hour.

The second crucial part of the tachymeter is the second hand or chronograph hand. This hand plays a crucial role as it points to the calculated speed or distance on the tachymeter scale once the chronograph is stopped.

How to Use a Tachymeter?

Employing a tachymeter in practical situations involves a basic understanding of the chronograph function and timing. Here’s a step-by-step guide:

  1. Starting and Stopping the Chronograph: This is the first step in using a tachymeter. Once an event—be it a car passing a mile marker or a runner crossing the start line—begins, you start the chronograph. When the event concludes or reaches a known distance, you stop the chronograph.
  2. Reading the Tachymeter Scale: After stopping the chronograph, the position of the second hand on the tachymeter scale gives you the measurement. If you’re measuring speed, the number on the scale shows the speed at which the event was moving in units per hour.
  3. Calculating Distance: If you’re using the tachymeter to measure distance, you need to maintain a constant speed. Start the chronograph and stop it when the second-hand points to your speed on the tachymeter scale. This signifies you’ve traveled one unit of distance—be it a mile or a kilometer.

Types of Watches with Tachymeters

Tachymeters are common features in a variety of watch types, notably in the following:

  1. Chronograph Watches: These are the most common type of watches featuring tachymeters due to their inherent timing functionality. Classic examples include the Omega Speedmaster and the Rolex Daytona.
  2. Aviation Watches: Tachymeters can be found on aviation watches, used by pilots for quick calculations during flight.
  3. Motor Racing Watches: Given their ability to calculate speed, tachymeters are a regular feature of motor racing watches. TAG Heuer’s Carrera and Monaco models are iconic in this realm.

Pros and Cons of a Tachymeter

Like any feature, a tachymeter comes with its advantages and disadvantages.


  1. Functional Utility: Tachymeters add an extra layer of functionality to watches, turning them into tools capable of calculating speed or distance.
  2. Aesthetic Appeal: Apart from functionality, the presence of a tachymeter scale can enhance the aesthetic appeal of a watch, giving it a sporty and sophisticated look.


  1. Complexity: The use of a tachymeter might be complex for some, requiring an understanding of its functionality.
  2. Limited Practical Use: In our digital age, the necessity for manual speed or distance calculations might be limited, rendering the tachymeter more of a stylistic element for some users.

Common Misconceptions About Tachymeters

One common misconception about tachymeters is that they can only measure speed. As we’ve seen, they can measure distance as well, provided the speed remains constant.

Another misconception is that tachymeters are exclusive to luxury watches. While often found on high-end models, many affordable watches also incorporate tachymeters.

Frequently Asked Questions (FAQ)

What is a tachymeter used for in real-life situations?

A tachymeter is used to calculate speed based on time traveled over a fixed distance, or vice versa. This can be useful in various scenarios, including timing laps at a race track, measuring the speed of a moving vehicle, or calculating the distance covered during a specific time frame.

Are tachymeters exclusive to certain brands or watch types?

Tachymeters are not exclusive to specific brands or watch types. While they are commonly found in chronograph watches, tachymeters can be featured in a wide range of timepieces, including both luxury and more affordable options.

How accurate is a tachymeter?

The accuracy of a tachymeter depends on the accuracy of the chronograph movement in the watch. High-quality watches with precise movements will provide more accurate measurements on the tachymeter scale.

However, it’s important to note that tachymeters are not as precise as dedicated measuring tools and should be used as approximate estimations.


Understanding the tachymeter on a watch unravels a facet of horology that reflects both the aesthetic and functional design inherent in watchmaking.

This often-overlooked component blends science and style, reminding us that a timepiece is more than just a tool to tell time. It is a testament to the meticulous craftsmanship that underlies the creation of every watch.

Sherry's editorial journey seamlessly merges with her passion for horology at WatchReflect. As a seasoned editor and watch enthusiast, she curates insightful guides that cater to novices and connoisseurs alike. With a penchant for research and a flair for storytelling, Sherry transforms horological complexities into engaging narratives. Her mission is to illuminate the path for those navigating the multifaceted realm of timekeeping.

0 0 votes
Article Rating
Notify of

Inline Feedbacks
View all comments
Would love your thoughts, please comment.x