What Is A Tachymeter On A Watch?

The concept of a tachymeter might be new to some, but it’s a common feature found on many wristwatches, primarily those meant for sports or aviation.

A tachymeter serves a crucial function – it measures speed based on time traveled over a fixed distance. The mechanism is surprisingly simple, given its useful application in various fields, from car racing to aviation.

A tachymeter, in essence, is a scale, typically engraved on the bezel of a watch, that enables swift calculations of speed.

With it, you can calculate your speed based on the time it takes to cover a set distance. The magic of this feature lies in its precision and its usability in multiple scenarios.

Delving into the world of tachymeters will not only allow you to understand your watch better but also explore the science and mathematics that go into creating these innovative timepieces.

What Is a Tachymeter on a Watch?

A tachymeter is an instrument that measures speed. It is based on travel time over a fixed distance. In the realm of wristwatches, a tachymeter is typically a scale inscribed on the rim (bezel) of a watch.

This feature has been a part of horological history since the early 19th century, with origins tracing back to the fields of engineering and aviation.

When you look at a watch with a tachymeter scale, you’ll notice numbers inscribed around the dial or the outer rim.

These numbers represent the Tachymeter scale and are used to calculate speed based on travel time.

How Does a Tachymeter Work?

The mechanism of a tachymeter is based on simple mathematics. It makes use of the basic relation between time and speed. The formula used is: speed equals distance divided by time.

Let’s consider an example: imagine you’re driving a car and want to calculate your speed. You start the stopwatch function on your tachymeter-equipped watch as you pass a mile marker.

As you pass the next mile marker, you stop the stopwatch. The second hand of your watch, pointing to the tachymeter scale, will now indicate your speed.

How to Use a Tachymeter

The use of a tachymeter requires just a couple of steps:

  1. Start the chronograph or stopwatch as you pass the start point.
  2. Stop the chronograph or stopwatch when you pass the endpoint.
  3. The point on the tachymeter scale where the second-hand points to is the speed.

For example, if it takes 35 seconds to travel one mile, then according to the Tachymeter scale, your speed is approximately 103 mph.

Why Is a Tachymeter Important in a Watch?

A tachymeter is a handy tool for anyone requiring speed and distance calculations. It finds its use in various fields like car racing, cycling, navigation, and even in some industrial processes.

Having a tachymeter on your watch allows you to perform these calculations instantly. For a racing enthusiast, it means being able to calculate their speed without relying on additional gadgets. For a pilot, it can serve as a backup for speed calculations in case of instrument failure.

Choosing a Watch with a Tachymeter

Choosing a watch with a tachymeter depends on your personal needs and style. Here are a few things to consider:

  1. Functionality: Ensure the watch has a fully functional chronograph or stopwatch – a prerequisite for using the tachymeter.
  2. Design: Tachymeters can be on the watch dial or bezel. Consider the design aesthetic that appeals to you. Some watches have a more prominent tachymeter scale, while others have a more subtle design.
  3. Accuracy: Look for watches with reliable and accurate tachymeter scales. Consider brands known for their precision and quality craftsmanship.
  4. Functionality: Check if the tachymeter scale is easily readable and if the watch offers additional features that complement its use, such as a date display, luminous hands, or water resistance.
  5. Budget: Set a budget and explore watches within that range. There are options available at various price points, ensuring that you can find a watch with a tachymeter that suits your budget.

Some popular brands known for producing watches with tachymeters include Rolex, Omega, TAG Heuer, Tissot, and Seiko. Research specific models from these brands and read reviews to determine the best choice for your needs.

Frequently Asked Questions About Tachymeters

Can a tachymeter be used for distance measurements?

No, a tachymeter is specifically designed for measuring speed based on time and distance. It is not suitable for direct distance measurements.

What are the limitations of a tachymeter?

Tachymeters work best for measuring speeds within a specific range. Extremely high or low speeds may not be accurately calculated using a tachymeter.

Additionally, variations in external factors like terrain, weather conditions, and acceleration rates can affect the precision of the measurement.

Can I use a tachymeter on any watch?

Not all watches come equipped with a tachymeter. It is typically found on watches designed for specific purposes such as racing, aviation, or sports.

However, some fashion watches may also incorporate a tachymeter for aesthetic purposes, even if they don’t have a functional chronograph.

Are there alternative methods for speed calculations?

Yes, there are alternative methods for calculating speed, such as GPS devices, smartphone apps, or dedicated speedometers.

However, a tachymeter on a watch offers the convenience of instant speed calculations without relying on external devices.


In conclusion, a tachymeter on a watch is a practical tool for measuring speed based on time and distance. It has a rich history and finds utility in various fields, from motorsports to aviation.

By understanding how a tachymeter works and how to use it, you can harness the power of this feature to calculate speed on the go.

When choosing a watch with a tachymeter, consider factors such as functionality, design, accuracy, and budget. By finding the right watch that suits your needs and preferences, you can make the most of this useful feature.

Remember, while a tachymeter is a valuable tool, it has limitations, and external factors can affect its accuracy. Nonetheless, it remains a fascinating feature that adds functionality and style to a watch.

So, the next time you glance at your watch and see the tachymeter scale, you’ll have a newfound appreciation for the science and precision behind this ingenious horological feature. Embrace the world of tachymeters and let your watch become a reliable companion for speed calculations.

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.

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