How to Use a Chronograph and Tachymeter on a Wristwatch

A tachymeter is a device that measures the speed of rotation or revolution, and thus it can be used to measure automotive speeds. A chronograph is an instrument that consists of two needles: one connected to a rotating pointer and the other connected to an oscillating mechanism which indicates hours, minutes and seconds on a dial.

The “how to use a tachymeter on a watch” is an article that discusses how to use the chronograph and tachymeter on a wristwatch.

We spoke about “complications” in our guide to men’s wristwatches, which are the many additional functionalities on a watch that go beyond merely telling time. A chronograph and a tachymeter are two complexities that are often seen on racing or pilot timepieces.

They undoubtedly add to the cool factor of your watch, but they’re not just for show. Understanding how these two watch complexities interact may transform your watch into a useful measurement instrument.

Continue reading if you’re perplexed by your chronograph watch’s dials and have no clue what the tachymeter numbers on the bezel imply. We’ll go through everything in detail below.

What Is a Chronograph and How Do I Use It?

The term “chronograph” is just a fancy way of saying “stopwatch.” In the early twentieth century, they were introduced to timepieces to enable racing drivers and pilots to time themselves and each other. Astronauts wore chronograph timepieces on their wrists during America’s golden era of space exploration. For example, on their risky voyage back to Earth, Apollo 13 astronaut Jack Swigert utilized the chronograph on his Omega Speedmaster to time a major course adjustment.

It’s simple to use a chronograph. To start or stop the stopwatch, just click the start/stop button on the side of the watch; to reset the stopwatch, simply press the bottom button.

Understanding what the numerous sub-dials that make up the chronograph imply is the more difficult element.

A second hand, a minute hand, and an hour hand are frequently seen on watch chronographs. (Some chronographs just feature a minute hand and a second hand.) As an example, I’ll use an Omega Speedmaster (supplied by Crown and Caliber) with three chronograph hands.)

Parts anatomy of a chronograph watch.

On a chronograph watch, the second hand is the long, thin middle hand. Unlike the second hand on non-chronograph watches, this one only moves when the stopwatch is started.

“Where does a chronograph watch keep track of the seconds of the current time?” you may wonder. On the face of a watch, this is done on one of the sub-dials. On this Speedmaster, the current time is shown by the second hand on the right-hand subdial.



It’s worth noting that the right sub-second dial’s hand continues to move even while the chronograph’s second hand is stopped, and that the chronograph’s second hand only begins when you press the chronograph’s start button.

On this watch, the minute hand is on the left-hand subdial of the chronograph. It displays how many minutes have elapsed since the stopwatch was started. It can monitor for up to 30 minutes, as you can see.

On this watch, the chronograph’s hour hand is located on the bottom, middle sub-dial. It displays the number of hours since you began your stopwatch.

What Is a Tachymeter and How Do I Use It?

How to Use a Tachymeter on a wristwatch.

Okay, so using a chronograph is simple. It’s nothing more than a stopwatch.

Now we’ll look at tachymeters. It takes a little mental work to figure out how to use them, but once you can, you’ll be able to track things like speed and distance traveled, as well as fuel usage (if you have a special ruler slide tachymeter bezel).


A tachymeter is a scale etched around a watch’s bezel or on the outer edge of the main dial. The following is the formula for making this scale:

3.600 (number of seconds in an hour)/elapsed time in seconds = tachymeter scale value

You may use the scale to convert elapsed time (measured in seconds per unit) to speed (in units per hour).

Most tachymeter scales only function and are valid for elapsed periods between 7.2 and 60 seconds. At roughly the 7.2-second hash, the scale on this Speedmaster starts at 500. The tachymeter won’t function for you if you’re attempting to measure the speed of anything that takes less than 7.2 seconds to complete. You can still use a tachymeter to find out the speed for tasks that take longer than 60 seconds; you’ll simply have to perform some arithmetic. I’ll get to it in a minute.

Remember that a tachymeter can only measure known distances up to one mile or one kilometer. You can calculate the speed of items that traverse shorter or longer distances if you perform some arithmetic.

Let’s look at how a tachymeter may be used to measure speed and distance in a few different situations.

How to Measure Speed with a Tachymeter

To use a tachymeter to determine the speed of an item, you must first determine the fixed distance between two places. Assume you’re at a racetrack and the distance between turns 1 and 2 is one mile. You can calculate a car’s average speed using this information.

Push the start button on your chronograph as soon as the automobile reaches turn 1. When it reaches turn 2, put a halt to it. The automobile took 40 seconds to get from turn 1 to turn 2 according to your chronograph.

Using a tachymeter on a wristwatch.

When you look at your tachymeter on your bezel, 40 seconds corresponds to the 91 hash mark. That indicates the automobile was moving at an average speed of 91 mph from turn 1 to turn 2.

The tachymeter is a neutral scale that may be used for various measurement units such as kilometers. Let’s imagine the racetrack you’re visiting is measured in kilometers. You’re aware that the distance between turns 1 and 2 is precisely one kilometer.

Start the chronograph as soon as the automobile reaches turn 1. Stop it when it reaches the second turn.

Closing of chronograph and tachymeter on a omega wristwatch.

The automobile took 22 seconds to get from turn 1 to turn 2 according to your chronograph. Between turn 1 and turn 2, the automobile averaged 180 km/h, which corresponds to the 180 hash point on your tachymeter bezel.

When monitoring elapsed periods over distances less than 1 mile or 1 kilometer, you’ll need to conduct some arithmetic to figure out the average speed. Assume you’re at Thunder Road in Barre, VT, watching a stock car race. It’s barely a quarter-mile long.

 Closing of chronograph and tachymeter on wristwatch.

When a vehicle reaches the start/finish line, you start the chronograph and stop it when it completes a completed lap. On the quarter-mile track, the automobile completed a lap in 16 seconds. On the tachymeter scale, 16 seconds corresponds to 225. There’s no chance the automobile was traveling 225 miles per hour; remember that the track was just a quarter of a mile long to obtain the accurate average speed. So we’ll need 14 out of 225, or 56.25. The automobile was traveling at a rate of roughly 56 miles per hour.


What should you do if a measurement takes longer than 60 seconds? Remember that the tachymeter scale is only appropriate for measuring elapsed periods up to a minute because of the way it’s set up.

You can still use a tachymeter to measure average speed for tasks that take longer than that with a little math. Let’s imagine you’re watching a one-mile horse race and you’re curious about the winning horse’s average speed. In 1 minute 34 seconds, or 94 seconds, he ran the mile.

With our tachymeter, 94 seconds is too lengthy to acquire a speed. But let’s look at his speed over a half-mile. We may estimate that the horse completed half a mile in 47 seconds (94 seconds divided by 2 = 47 seconds). The tachymeter’s range is 47 seconds, which corresponds to the 75 hash mark. We need to divide 75 by 2 to obtain the average speed per mile for the whole mile, which comes out to 37.5 mph.

A tachymeter may be used to calculate the time it takes to create “x” number of widgets in an hour, in addition to measuring the speed of moving objects such as vehicles, humans, or racing horses. For example, if you want to know how many watches a watch manufacturer can produce each hour, use your chronograph to time how long it takes to build a watch from start to finish. It just takes 55 seconds thanks to automation. 55 seconds corresponds to 65 seconds on the tachymeter scale. As a result, a watchmaker can produce 65 watches each hour.

Isn’t it cool?

How to Measure Distance with a Tachymeter

A tachymeter may be used to measure distance traveled as well as the speed of an item.

To accomplish so, you must first choose your travel speed, which must be maintained at all times.

 Using a Tachymeter to Measure Distance on wristwatch.

Assume you’re driving at 75 mph on the highway. Begin your chronograph with the second hand. When the second hand on the tachymeter scale hits 75, you’ve walked one mile.

Again, for this to function, you must maintain a steady pace throughout.

Those dials on your chronograph watch don’t have to be so daunting anymore, and you may utilize and enjoy them for their purpose as well as their aesthetics.



A tachymeter is a tool that measures speed. It’s used in many different fields, for example when racing cars or bikes. The “how to use tachymeter on apple watch” article will show you how to use the device and how it works.

Frequently Asked Questions

How do you use a chronograph and tachymeter on a wrist watch?

A: This is a tool that measures speed and distance. A timepiece with this type of watch faces has been around since the late 1800s. It consists of two scales on opposite sides of the face, which measure elapsed time or travel speed in units called milliseconds per hour (ms/h).

How do you use a tachymeter on a wrist watch?

A: To measure the distance traveled by a person as they walk, you can use a tachymeter on their wrist watch. This will allow them to estimate how far they have walked during an extended period of time so that they can rest or take breaks if needed

What is the purpose of tachymeter in watches?

A: The tachymeter is a dial on the watch face used to measure speed by counting rotations of the bezel. It helps determine how fast you are going, for example when youre running or cycling

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