How to Read a Watch Bezel: Complete Guide to Bezel Functions and Scales

I remember the first time I got a dive watch with a rotating bezel. I was so excited about how cool it looked, but I had absolutely no idea how to actually use it. The numbers and markers seemed straightforward enough, but I couldn’t figure out what I was supposed to do with them. Was I missing something obvious? (Spoiler alert: yes, I was.)

If you’ve ever wondered what all those markings on watch bezels are actually for – or if you’ve had a watch with a special bezel for years but never quite figured out how to use it – you’re not alone. Watch bezels aren’t just decorative; they’re functional tools designed to help with everything from timing pasta to calculating speed or even navigating with a compass.

In this guide, I’ll break down the different types of watch bezels, explain exactly how to use each one, and share some practical, real-world applications that might make you appreciate that rotating ring around your watch in a whole new way.

Dive Bezels: The Classic Rotating Timing Bezel

The most common type of functional bezel is the unidirectional rotating bezel found on dive watches. At first glance, it’s just a ring with numbers from 0 to 60, but it’s actually an ingenious analog timer.

How to Read a Dive Bezel

A standard dive bezel features:

• Minute markings from 0 to 60
• A prominent triangle or pip at the zero/60 position
• Unidirectional (counterclockwise only) rotation on true dive watches
• Sometimes more prominent markings at 15, 30, and 45 minutes

How to Use a Dive Bezel for Timing

The basic operation is wonderfully simple:

1. Rotate the bezel so the zero marker (triangle/pip) aligns with the minute hand
2. As time passes, the minute hand moves around the dial
3. Read the elapsed time against the bezel markings

For example, if you align the zero marker with the minute hand at 2:35, when the minute hand points to the “20” mark on the bezel, 20 minutes have elapsed.

The beauty of this system is that you can see both the current time AND how much time has elapsed at a glance – no need to remember your starting time and do mental math.

Why Dive Bezels Rotate in Only One Direction

True dive watch bezels only rotate counterclockwise, and there’s a critical safety reason for this: if the bezel gets bumped during a dive, it can only move in a direction that displays LESS remaining time, not more. This ensures a diver wouldn’t mistakenly think they have more air than they actually do – a potentially life-saving feature.

Practical Uses for Dive Bezels Beyond Diving

I’ve never used my dive bezel for actual scuba diving, but I use it several times a week for:

• Timing parking meters
• Cooking (it’s perfect for pasta!)
• Keeping track of meeting durations
• Monitoring work breaks
• Timing workouts

Once you get into the habit of using your dive bezel, you’ll find yourself reaching for it constantly. It’s often faster and more convenient than pulling out your phone or setting a dedicated timer.

GMT Bezels: Tracking Multiple Time Zones

GMT or 24-hour bezels help track a second time zone and are typically found on travel watches. They function differently from dive bezels but are just as useful in daily life.

How to Read a GMT Bezel

A GMT bezel typically features:

• Numbers from 1-24 representing hours in a day
• Sometimes color coding (blue/black or red/blue) to represent day/night hours
• Either bidirectional rotation or fixed (depending on the watch design)

How to Use a GMT Bezel with a GMT Hand

On watches with a dedicated GMT hand (a second hour hand that makes one full rotation per 24 hours):

1. The main hour hand shows your local time as normal
2. The GMT hand points to the hour on the 24-hour scale (bezel or internal ring)
3. If the bezel rotates, you can adjust it to track a third time zone

For example, if you’re in New York (ET) and want to track London (GMT) and Tokyo (GMT+9):

• Set the main hands to New York time
• The GMT hand will point to the corresponding hour on the 24-hour scale for London
• Rotate the bezel 9 clicks counterclockwise to read Tokyo time where the GMT hand points

Using a 24-Hour Bezel Without a GMT Hand

Some watches have a 24-hour bezel but no dedicated GMT hand. In this case:

1. Set the watch to your local time as normal
2. Rotate the bezel so the hour corresponding to the second time zone aligns with the hour in your current time zone
3. Read the second time zone by seeing which bezel number aligns with the current hour

This method is less intuitive but works once you get the hang of it.

Practical Applications for GMT Bezels

I use my GMT watch for:

• Tracking home time while traveling
• Knowing when family in different time zones are awake
• Planning international conference calls
• Avoiding waking up friends overseas with ill-timed messages

For remote workers or anyone with international connections, a GMT function saves you from constantly calculating time differences in your head.

Tachymeter Bezels: Measuring Speed or Distance

Found most commonly on chronograph watches, the tachymeter scale looks intimidating with its seemingly random numbers (400, 300, 240, 200…), but it’s actually a clever analog calculator.

How to Read a Tachymeter Bezel

A tachymeter bezel typically:

• Features a scale of decreasing numbers from 400+ down to 60
• Is fixed (non-rotating)
• Works in conjunction with the chronograph (stopwatch) function
• Calculates units per hour (speed or production rate)

Using a Tachymeter to Calculate Speed

The classic use case for a tachymeter is calculating speed:

1. Start the chronograph when passing a mile or kilometer marker
2. Stop the chronograph when passing the next marker
3. The position of the chronograph second hand on the tachymeter scale shows your speed in units per hour

For example, if it takes 30 seconds to travel one kilometer, the chronograph hand will point to 120 on the tachymeter scale, indicating 120 kilometers per hour.

Using a Tachymeter to Calculate Productivity or Distance

The tachymeter can also be used to calculate:

• Production rates: Start the chronograph when production begins, stop after producing one unit, read units per hour
• Distance: If you know your speed, start the chronograph and stop it after traveling for a specific time. The reading on the tachymeter multiplied by the time traveled (as a fraction of an hour) gives you the distance.

Limitations of Tachymeter Scales

Tachymeters typically only work for events taking between 7.2 seconds and 60 seconds. Outside this range, the readings become either too crowded to read accurately or fall off the scale entirely.

Count-Up vs. Count-Down Bezels

While most dive bezels are count-up (starting from zero and counting elapsed time), some watches feature count-down bezels, which work in the opposite direction.

How to Use a Count-Down Bezel

1. Rotate the bezel to align the minute hand with the desired countdown duration
2. When the minute hand reaches the zero marker, time’s up!

This is particularly useful for events with a fixed duration where you want to know how much time remains rather than how much has elapsed.

Compass Bezels: Navigation Using Your Watch

Some watches feature compass bezels, which aren’t about time at all but can help you navigate using the sun.

How to Use a Compass Bezel in the Northern Hemisphere

1. Hold the watch horizontally
2. Point the hour hand toward the sun
3. The point halfway between the hour hand and 12 o’clock points south
4. Align the “S” marker on the bezel with this halfway point
5. The bezel now shows all directions

Using a Compass Bezel in the Southern Hemisphere

The process is similar, but:

1. Point the 12 o’clock marker toward the sun
2. The halfway point between 12 and the hour hand points north
3. Align the “N” on the bezel with this halfway point

This method isn’t precise enough for serious navigation but can give you a general sense of direction in a pinch.

Slide Rule Bezels: The Analog Calculator

Found on watches like the Breitling Navitimer, slide rule bezels are the most complex watch bezels, essentially putting a circular slide rule calculator on your wrist.

Basic Slide Rule Operations

The two scales (one on the bezel, one on the dial) work together to perform:

• Multiplication: Align the first number on the outer scale with the second number on the inner scale, then find the result on the outer scale aligned with the index marker
• Division: Align the dividend on the outer scale with the divisor on the inner scale, then read the result on the outer scale aligned with the index marker
• Conversion: Most slide rules have additional markers for converting between units (km/miles, gallons/liters, etc.)

Practical Uses for Slide Rule Bezels

While smartphones have made these calculations easier, a slide rule bezel can be used for:

• Tip calculations
• Currency conversion
• Fuel consumption calculations
• Flight planning (its original purpose)

Mastering a slide rule bezel takes practice, but it’s a fascinating analog technology that works without batteries or connectivity.

Pulsometer Bezels: For Medical Professionals

Some watches, particularly those marketed to medical professionals, feature pulsometer scales for measuring heart rate.

How to Use a Pulsometer Bezel

1. The scale is typically calibrated for counting a specific number of heartbeats (often 15 or 30)
2. Start the chronograph and begin counting heartbeats
3. After counting the specified number, stop the chronograph
4. Read the heart rate in beats per minute where the second hand points

For example, if the pulsometer is calibrated for 15 beats and the second hand stops at 75, the heart rate is 75 BPM.

Telemeter Bezels: Measuring Distance Using Sound

Less common today, telemeter bezels were originally used to calculate the distance to artillery fire or thunderstorms based on the speed of sound.

Using a Telemeter Bezel

1. Start the chronograph when you see an event (like lightning)
2. Stop it when you hear the sound (thunder)
3. Read the distance in kilometers or miles on the telemeter scale

This works because light travels essentially instantaneously for short distances, while sound travels at approximately 343 meters per second (1,125 feet per second).

Caring for Your Watch Bezel

To keep your bezel functioning properly:

• Rinse after saltwater exposure: Salt can cause corrosion in the bezel mechanism
• Clean occasionally: Use a soft toothbrush to remove dirt from the bezel edge
• Don’t force rotation: If a bezel is stiff, clean it first before applying more force
• Check water resistance: A damaged bezel can compromise water resistance

Common Bezel Questions and Problems

My Bezel Is Hard to Turn. Is That Normal?

Some bezels are intentionally stiff to prevent accidental rotation, but excessive resistance usually indicates:

• Dirt/salt buildup under the bezel
• Dried gasket lubricant
• Damage to the bezel mechanism

A gentle cleaning with fresh water often solves this issue. For persistent problems, consider having your watch serviced.

Can I Replace or Modify My Bezel?

Many watch enthusiasts customize their bezels:

• Bezel insert replacement: Changes the look or function of the watch
• Bezel mechanism service: Can improve action or fix damaged components
• Aftermarket bezels: Available for popular models like SKX divers

Modifying bezels is a common entry point to watch modding, though it does require some specialized tools.

My Bezel Has Faded. Can This Be Fixed?

Faded aluminum bezel inserts are common on older watches (especially vintage dive watches) and considered part of the watch’s patina. You can:

• Embrace the fading as character
• Replace the insert with a new one
• Look for replacement “ghost bezels” that replicate a faded look

Modern ceramic bezels are designed to resist this type of fading.

The Evolution of Watch Bezels

Watch bezels have come a long way:

• 1920s-30s: Early rotating bezels appear on pilot watches
• 1950s: The dive bezel is standardized with the Blancpain Fifty Fathoms and Rolex Submariner
• 1960s: GMT bezels gain popularity with increased international travel
• 1970s: Plastic and aluminum inserts become common
• 2000s-present: Ceramic, sapphire, and other scratch-resistant materials revolutionize bezel durability

Final Thoughts: The Analog Utility of Watch Bezels

In our digital age, there’s something uniquely satisfying about using an analog tool like a watch bezel. While your smartphone can perform all these functions (and many more), a well-designed watch bezel offers an immediate, tactile interface that doesn’t require unlocking a screen, opening an app, or worrying about battery life.

I’ve found that once I learned how to actually use the bezels on my watches, I began to appreciate these timepieces on a completely different level. They transformed from simple time-telling devices or fashion accessories into functional tools that I use throughout the day.

Whether you’re timing a presentation with a dive bezel, checking when your overseas friend wakes up with a GMT bezel, or calculating a tip with a slide rule bezel, these analog computers on our wrists represent a perfect blend of form and function that has stood the test of time.

Do you regularly use your watch bezel? What’s your favorite type or most useful application? Share your experiences in the comments below!

SEE also

Rolex
Omega
Patek Philippe
Audemars Piguet
TAG Heuer
Seiko
Longines
Tissot
Casio
Citizen