What Is a Tachymeter and How to Use it?

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what is a tachymeter

Have you ever wondered what that circular scale on the bezel of your watch is for? That’s the tachymeter, a handy tool that allows you to measure speed and distance based on time.

Whether you’re a watch enthusiast or just curious about this fascinating feature, this article will provide you with everything you need to know about tachymeters and how to use them. So, buckle up and get ready to learn about one of the most useful tools on your wrist!

What is a Tachymeter?

A tachymeter is a watch mechanism that works with a scale, usually called a tachymeter scale which keeps track of the period of time (travel time) that has elapsed. Then, basic math functions measure the speed at which a person or an object travels.

It is typically placed around the edge of the watch face and is used in conjunction with a chronograph function.

When Were Tachymeters Added to Chronograph Watches?

Chronograph watches and tachymeters have a long, definitive history, albeit an interesting one. Shortly after chronograph watches were introduced, tachymeters were added to certain models as one of their defining characteristics, so much so that the world was introduced to a wide variety of tachymeters that could be found on chronograph watches.

At some point in the 20th century, tachymeters became rather commonplace on chronograph watches and proved to be quite popular with people from certain professions and backgrounds, such as those in aviation, journeymen, racing enthusiasts, and even watch connoisseurs.

Over time, all the big watch brands like Rolex or Patek Philippe started putting out watch models with tachymeters as part of their construction.

Also, since digital watches weren’t a thing back then, racing watches with tachymeters used to be all the rage at sporting events such as races and horse riding competitions.

How Does a Tachymeter Work?

 Leather Strap Watch

Many tachymeters are usually a part of chronograph watches, where the bezel is referred to as a “tachymeter bezel.” Most of these constructions are found on the outer bezel of a chronograph watch, and they help you calculate the kilometers per hour or the miles per hour at which you’re traveling.

It’s an instrument used for speed measurement that has been helping travelers for centuries. You mostly see them on chronograph watches because you can properly measure your speed if you’re able to stop and start the time, and chronograph watches offer you that option.

Once you’ve measured the time you’ve been traveling, you can then measure the distance to get your average speed in whatever unit of measurement the tachymeter offers. You might have to perform a minor calculation here and there, but that’s about it.

Think about it this way. You’re riding a motorcycle on a race track and want to check the average speed you’re traveling at. Let’s say you ride for 1 kilometer, and the tachymeter gives you a reading of 80. This means that you traveled 80 kilometers per hour and rode your motorcycle for 12.5 seconds.

The tachymeter operates on a simple speed–distance/time formula, so you can shuffle this formula around to calculate what you’re exactly looking for. For people on a minute track or a race, the tachymeter is a simple, easy, and unique way to keep track of their average speed.

Types of Tachymeter Watches

We’re going to look into the different types of tachymeters you can find on most chronograph watches out there. The good news is that they can be broadly categorized into three different types. Let’s get right into it.

1. Fixed Bezel Tachymeter

The simplest sort of tachymeter is the fixed bezel tachymeter watch, which is usually mounted or placed on the outer edge of the watch‘s fixed bezel. There are also variations where the tachymeter can be found on the inner bezel of the watch.

Remember, the distinguishing characteristic here is that these tachymeters are only found on watches with fixed bezels.

Also, to properly use most fixed bezel tachymeters, you must set the watch’s chronograph hand to zero. After that, you must drive around or move for a distance of one kilometer before you read the value the tachymeter shows you. At that point, the tachymeter will show you the approximate speed you were going at.

Of course, you can then use this reading to find the approximate distance you traveled with a simple calculation. The most prominent watch brands around the world use fixed bezel tachymeters.

2. Snail-type Tachymeter

Next up is a tachymeter with slightly more detailed construction. One difference between them and fixed bezel tachymeters is their position on the watch. Usually, these tachymeters are mounted at the exact center of the watch dial.

There are several reasons why some people prefer snail-type tachymeters over fixed bezel tachymeters. The most prominent reason is that they’re better suited for measuring objects moving at slower speeds, as their name implies.

The snail-type tachymeter is the perfect option for objects moving at speeds under a mile or a kilometer per minute.

3. Moving Bezel Circumferential Tachymeter

The final type of tachymeter on our list is the moving bezel circumferential tachymeter. One particularly interesting thing about this tachymeter is that it’s very difficult to find on just any other watch.

The exclusive nature of this tachymeter adds to its overall appeal, making it a highly coveted item in the eyes of many collectors and watch enthusiasts.

The main functionality this tachymeter brings to the table is that it allows you to measure the average speed for every kilometer or mile that you travel in general or during a race. Just rotate the bezel, and it allows you to record the actual speed you’re going per mile and then gives you the overall average speed you were traveling at.

This tachymeter does away with the common complaint most people have with fixed bezel watches about how they’re only capable of calculating the speed you’re going at for one particular mile or kilometer before needing to be reset.

How to Measure Speed With a Tachymeter

This is the most common feature tachymeter watches are generally used for. Back in the day, racers and horseback riders would use tachymeter watches as a regular part of their routine. Even now, tachymeters are considered a unique and exciting way to track speed quickly and effectively.

If you’re looking to measure your speed with a tachymeter, it’s a bit more complicated than measuring the distance but not difficult.

Reset your tachymeter and figure out where the tachymeter is located on your watch. Once that’s done, check if your watch tells you the speed in kilometers per hour or miles per hour. This is important since you’ll be using one unit of distance to track your speed as you traverse it.

Next up, find two reference points with exactly one kilometer or one mile of distance between them. This is important because you’ll be measuring your speed across one kilometer or mile, which is what most average tachymeters allow you to do.

Start the chronograph once you pass the first reference point. The tachymeter will start measuring your speed as you travel. Stop the chronograph hand as soon as you pass the second reference point. Again, each tachymeter comes with specific instructions on how to start/stop it, but they’re generally very easy to figure out and use.

Check where the chronograph hand aligns with the tachymeter scale. That will tell you your speed across the distance you’ve traveled. If the hand aligns with 70 on the tachymeter, you are going at an average speed of 70 kilometers or meters per hour.

All in all, you can still use the speed = distance/time formula to calculate the total time you traveled. It’s pretty basic math and convenient for rapid speed or distance calculations.

How to Measure Distance With A Tachymeter

Gray Ladies watch

This is a secondary feature that most tachymeter watches are used for. We’ll talk about how you can easily measure your distance with a common tachymeter in just a few simple steps. Before you get into these steps, however, always remember to reset your tachymeter for an accurate reading.

One of the first things you need to do is locate where your tachymeter scale is on your watch. Depending on the watch type, you could find the tachymeter scale at the 6-second, 7-second, or 9-second mark. Most commonly, however, you’ll find it at the 7-second mark.

The second thing you need to do is observe your watch and figure out what units of speed the tachymeter uses. In most cases, this will either be kilometers per hour or miles per hour. Once you know this, you’re ready to measure your speed with just a little bit of mental math.

If it’s a standard fixed bezel tachymeter, start driving at a speed above 60 kilometers or miles per hour. The average tachymeter doesn’t measure speeds under 60 kilometers per hour unless it’s a snail-type construction. Also, you need to drive at a constant speed for this to be completely accurate.

Once you’ve started moving, start the chronograph. The machine will start measuring your distance immediately. Since you’re only measuring your distance, not your speed, you must now wait for the chronograph hand to reach a value equal to the speed you’re traveling at.

When the chronograph hand reaches the tachymetric value, you’ve traveled exactly one unit of distance. To put this into perspective, if you’re traveling at 85 kilometers an hour, you will have traveled exactly one kilometer once the chronograph hand is at the 85 mark on the tachymeter scale.

Frequently Asked Questions

Have certain questions about a tachymeter and how it works? We’ve compiled a list of the most frequently asked questions we get in this regard. Keep reading to find out more!

What types of watches usually have tachymeters?

The most common type of watches that come with tachymeters are racing watches that have historically been used in racing events and other competitive time-based sporting events.
One of the defining characteristics of these watches is that they’re pretty stylish and sleek, and tachymeters just add a layer of mechanical robustness and convenience to them.

What do the different markings on my bezel mean?

All the markings and numbers on your watch bezel have a purpose, even if it may not be immediately apparent. Some of these markers measure distance. Others measure speed.
There are also other things these markers indicate, but it depends on the type of watch and the company you’re purchasing it from.

What formula can I use to calculate my speed during travel?

The basic mathematical formula used for calculating speed is speed = distance/time. So one unit of speed equals one unit of distance divided by one unit of time. This formula is quite convenient since you can easily switch the variables in the equation depending on what you want to calculate.
For instance, if you want to calculate the time you’ve traveled when you know the distance and the speed you were going at, simply switch the formula to time = distance/speed.

What is a tachymeter, and what is it used for?

A tachymeter is a feature found on the bezel or dial of a watch with a chronograph function. It is used to measure the speed of an object over a fixed period of time, typically in seconds or distance units.

How does one use the tachymeter on a watch?

To use a tachymeter on a watch, start the chronograph’s stopwatch function and record the time it takes for an object to travel a known distance. Then, read the corresponding value on the tachymeter scale to determine the speed in units per hour.

What is the relationship between a tachymeter and a chronograph?

A tachymeter is a watch complication used to measure the speed based on the time it takes for an object to travel a known distance, and it is typically paired with a chronograph, which is a stopwatch function on the watch.

Can any watch with a chronograph feature include a tachymeter?

Not all watches with a chronograph feature include a tachymeter. A tachymeter is a specific feature that is found on certain timepieces, especially those designed for measuring speed and elapsed time.

What are some popular watch brands known for incorporating a tachymeter on their timepieces?

Some popular watch brands known for incorporating tachymeters in their timepieces include Omega, Heuer, and other well-known luxury watchmakers.

How does one read the tachymeter measurements on a watch?

To read the tachymeter measurements on a watch, determine the number of seconds or units it took for an object to travel a fixed distance, and then find the corresponding value on the tachymeter scale to calculate the speed.

What units are typically used for tachymeter measurements on a watch?

Tachymeter measurements on a watch are typically based on the number of seconds it takes for an object to travel a known distance, and the scale is calibrated in units per hour (e.g., kilometers per hour or miles per hour).

Are there specific steps to follow when using a tachymeter on a watch?

Yes, when using a tachymeter on a watch, it’s important to start the chronograph function, record the time it takes for an object to travel a known distance, and then use the tachymeter scale to calculate the speed based on the elapsed time.

What should one consider when using the tachymeter feature on a watch for the first time?

When using the tachymeter feature on a watch for the first time, it’s important to familiarize yourself with the specific tachymeter scale and its markings, as well as practice using the feature to accurately measure the speed of different objects or activities.

Final Thoughts

A tachymeter is an incredibly useful invention that changed how we looked at the utility of everyday wristwear. It brought a wave of innovation that pushed watch companies to innovate in many ways, particularly in ways that attempted to magnify the function utility watches could provide.

We hope you enjoyed this introduction to what is a tachymeter, how it works, and how you can use it for your own benefit.

Now that you know all about this, you’re pretty much ready to head out there and purchase a tachymeter watch of your own!

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I am the founder and chief editor of HappyWatchesNow.com. I aim to inform and help individuals to make informed choices when buying their watches. I want HappyWatchesNow to become a beacon of trust and authenticity in a world clouded by biases and commercial agendas.