Watch Sizing

Watches are typically measured in millimeters (mm), which might not be familiar to those of us without a lot of metric system experience. Any given watch typically has three measurements: case diameter, case thickness and band width.
Ex, At Amazon.com, you'll find these measurements listed in the Product Specifications section of each product detail page. For a comparison, a United States quarter measures 24.26mm in diameter (0.96 inches), comparable to an average-sized woman's watch, such as this women's TAG Heuer watch measuring 24mm (0.94 inches).

Here are some basic guidelines for thickness:
Thin: 4mm to 6mm (0.16 to 0.24 inches)
Average: 7mm to 11mm (0.28 to 0.43 inches)
Large: 12mm to 14mm (0.47 to 0.55 inches)
Extra-Large: 15mm to 18mm (0.59 to 0.71 inches)

While you can get a sense of a watch's size from its width measurement, be aware of the dial's design. Consider two watch cases that have the same measurement. One might appear larger because its dial extends to the very edge of the case, while the other seems smaller because it has a thicker bezel that frames the dial. Ultimately, this visual measurement is rather subjective.
One measurement you won't find is the weight of a watch, but one thing to keep in mind is that adding a metal bracelet will add to the watch's heft on your wrist. If weight is a concern, consider a bracelet and case made of titanium, a metal that's far lighter than stainless steel.

Watch Cases

Watch cases, the housing of the timepiece that contains the internal movement, can be made out of anything that's durably solid, but today's cases are primarily made of stainless steel. Stainless steel is quite durable and contains a bit of chromium to help protect the steel from corrosion and rust. Typically silver in color, it can be plated with a thin layer of gold (about 10 microns, or 1/1000 of a millimeter in thickness) in whole or in part for added accent. You can also find stainless steel cases in different colors, thanks to a process called ionic plating or PVD (physical vapor deposition) which usually gives it a matte finish.
The most popular form of gold is still yellow gold, but rose gold, featuring a pinkish tint due to a higher concentration of copper in its alloy mix, is gaining in popularity. When shopping for gold watches, pay attention to the fineness (or purity) of the gold as expressed in karats. A single karat equals 1/24 of the pure metal, so an 18 karat gold watch translates to 75 percent pure gold (whereas 14 karat gold equals 58 percent).
Titanium has become popular in higher-end watches as it's a bit more expensive and harder to work with. Offering a lighter shade of silver, titanium is 50 percent lighter than steel, but 30 percent stronger. For watch enthusiasts who have allergic reactions to stainless steel, titanium is an excellent alternative as it doesn't contain nickel (the allergen found in stainless steel). It's also a great choice for diving and water sports as it's very resistant to salt water corrosion. On the downside, it's a bit more apt to picking up scratches.
Additionally, you'll find watch cases made of precious metals, such as platinum (used in luxury watches) and sterling silver, ceramic, tungsten, aluminum (also very corrosion-resistant), and carbon fiber. Sport watch cases are typically made of hardened rubber, plastic, or resin, and are a good option for use during more rugged activities.

Shapes
Wrist watches come in a few basic shapes: round, square, and rectangular. A fourth popular shape is Tonneau, which has a tall orientation with a flattened top and bottom, and bulging sides that resemble a barrel. Round watches are the direct descendent of the pocket watch and are the most popular shape. The majority of sport watches will be circular as it's the shape that's easiest to make water-resistent. Square watches provide more of a canvas for adding decoration to fashion watches. Rectangular watches are considered dressier as they can be better hidden under the sleeve. Tonneau-shaped watches present a unique retro style and are also considered dressy thanks to their slimmer profile.

Watch Features

At its most basic, a watch is there to conveniently remind you of the time with just the flick of your wrist. But for more timing capabilities, you can add what are known in chorological terms as complications, which run the gamut of the stopwatch-like chronograph to a display of moon phases to a calendar window. Below are some of the most popular complications found in today's watches.

Calendar
One of the most ubiquitous complications, calendar watches include a small window showing the date, typically placed on the dial at 3 o'clock. You'll also find some date watches that include the day of the week in a separate window. Most calendars count out to 31, requiring you to manually reset the date on those months that don't have 31 days.
Some date watches have smarter calendar complications. An annual calendar can run for a full year without resetting until you get to March (as February's 28 or 29 days throws it off). But you won't have to worry about resetting the date for a long time with a perpetual calendar watch, programmed to automatically adjust for the varying lengths of months as well as leap years to the year 2100.

Chronograph
Another popular complication in today's watches is the chronograph, which enables you to use your watch as a stopwatch to time specific events as well as multiple laps. To start timing, you'll press one of the pushers on the side of the watch case. Depending on the watch, you may press that pusher or a second one to stop the timing. Chronographs have two or three smaller subdials (also called totalizers or registers) placed on the dial face that display the seconds, minutes, and hours. Quartz chronographs can measure events down to 1/10 of a second, while their automatic counterparts can get as accurate as 1/5 of a second. In addition to timing your exercise, chronographs can be paired with a tachymeter scale (placed around the outside of the dial or on the rim of the bezel) to determine the average speed covered over a specified distance.

Note: Don't confuse the term "chronometer" with a chronograph. Where a chronograph is part of a watch's mechanics, a chronometer is a timepiece that's been certified by the Controle Officiel Suisse des Chronometers (or COSC, the official Swiss chronometer inspection body) as being highly accurate. Only three percent of watches produced in Switzerland are chronometer-certified. To achieve this highly coveted certification, the movements are subjected to numerous tests over a period of 15 consecutive days and nights, in five positions and at three different temperatures. And a chronometer may or may not be a chronograph.

Moon Phase Indicator
More of an ornamental complication, lunar phase watches depict the illuminated portion of the moon as seen on Earth via an illustrated disc that rotates beneath the dial. Once set, the indicator will rotate completely once every 29 days, 12 hours, and 44 minutes.

Dual Time Zone and World Time
If you do a lot of traveling, a dual time zone watch (also called a GMT watch) can be handy as it will show you the current time where you are as well as the time in a second time zone. This is done either via an extra hand, twin subdials, or a 24-hour scale placed on the dial. If you need to keep track of business time on several continents, a world time watch typically displays 24 city names placed on the dial or bezel to represent each individual time zone. You can read the hour in a particular time zone by looking at the scale set next to the city that the hour hand is pointing to.

Multifunction
This is a generic term for a non-chronograph watch that displays information such as month, day, and date in two or three subdials.

Note: Chronographs, which are an added complication that provides stopwatch functionality, can be found on both quartz and automatic watch movements. Quartz chronographs can provide more accuracy, timing events down to 1/10 second compared to an automatic movement's 1/5 second accuracy. Learn more about chronographs and other watch complications.

Shock-Proofing of watch

Most watches are sturdy enough to protect against normal everyday wear and tear, including light bumps. If you’re going to be engaging in intensive athletic activity, you may want a watch that is also shock-proof. For example, G-Shock by Casio is an extensive line of shock-proof watches.



Drop TestShock-resistance confirmed by free-fall test simulating actual usage conditions.










Vibration TestVibration resistance confirmed by vibrating for 20 minutes or longer with a testing machine generating a 19.6 m/s sine wave.









Hammer TestShock-resistance further confirmed by striking the watch at rest with a hammer in a 180-degree rotating trajectory.








Water-Resistance TestRetention of water-resistance capability confirmed by underwater pressurization at 200 meters for 5 minutes or longer.

Other Movements of watch

Eco-Drive
Eco-drive was created by Citizen and has earned recognition in the watch industry as a leader in ecologically-friendly timekeeping. Citizen Eco-Drive runs continuously in any kind of light (natural or artificial) for a lifetime of use without a battery. The Eco-Drive movement absorbs light through the crystal and dial. Inside the watch, a solar cell converts the light to the energy required to make the watch run.

Kinetic
Referring to the Seiko line of Kinetic watches, this innovative technology has a quartz movement that doesn't use a battery. Movement of the wearer’s wrist charges a very efficient capacitor that powers the quartz movement. Once the capacitor is fully charged, men’s models will store energy for 7-14 days without being worn and ladies' models will store energy for 3-7 days. The watch alerts the wearer to a low capacitor charge when the second hand starts to move in two-second intervals.
Over the past 20 years, Seiko has created a suite of Kinetic movements, each bringing unique features to the consumer.
It was at the 1986 Basel Fair that Seiko unveiled its first Kinetic prototype. Introduced under the trial name of AGM, it was the first watch in the world to convert kinetic movement into electrical energy. It was the first step in a development that, 20 years later, has made Kinetic synonymous with environmental friendliness, high performance and long-lasting convenience to a generation of users worldwide. From the launch in 1988 of the first commercially available watch (then under the new name AGS) until today, over 8 million Kinetic watches have been sold (as of 2007).
In 1998, Kinetic Auto Relay was released, extending the 'at-rest' operating period of the watch to a remarkable 4 years. 1999 brought the launch of the Ultimate Kinetic Chronograph, a masterpiece which fused the very best of Seiko's mechanical and electronic matchmaking skills, and in 2003, another Kinetic Chronograph was launched. At Baselworld 2005, the Kinetic Perpetual made its first appearance, combining Kinetic convenience and longevity with a perpetual calendar, correct to the year 2100. Most recently in 2007, Seiko's emotional technology Kinetic Direct Drive was introduced.

Swiss Movements
It might be stereotypical, but it's true. Many of the world's finest and most accurate timing movements, be they quartz or automatic, are created in Switzerland. Swiss-manufactured movements are found in a wide swath of watches sold worldwide, but a timepiece can only be awarded the coveted Swiss-made label if the movement is made and then subsequently encased in Switzerland.

What is Automatic watch?

Automatic watches are made up of about 130 or more parts that work together to tell time. Automatic movements mark the passage of time by a series of gear mechanisms, and are wound by the movement of your wrist as you wear it. The gear train then transmits the power to the escapement, which distributes the impulses, turning the balance wheel. The balance wheel is the time regulating organ of a mechanical watch, which vibrates on a spiral hairspring. Lengthening or shortening the balance spring makes the balance wheel go faster or slower to advance or retard the watch. The travel of the balance wheel from one extreme to the other and back again is called oscillation. Lastly, automatic movements come in different types, including movements that are Swiss-made, Japanese-made, and more.
Also referred to as self-winding, watches with automatic movements utilize kinetic energy, the swinging of your arm, to provide energy to an oscillating rotor to keep the watch ticking. They're considered more satisfying to watch collectors (horologists) because of the engineering artistry that goes into the hundreds of parts that make up the movement. If you do not wear an automatic watch consistently (for about 8 to 12 hours a day), you can keep the watch powered with a watch winder (a great gift for collectors). You should refer to your owner's manual for recommended service intervals.

Automatic Watch Maintenance
Although automatic (also called "mechanical") watches do not have batteries, some easy-to-follow maintenance is necessary for continued and long-lasting good use.
Self-winding automatic watches depend on the movement of the arm to operate and do require some winding, even if you wear your watch on a daily basis.
If you wear your automatic watch every day, it is best to wind it once every two weeks to keep the wheels in motion and oil fluid. Simply wind the crown (the same knob used to adjust the time and date) until you meet slight resistance If you do not wear your automatic watch every day, you should try to wind it at least twice a week to ensure continuous operation, as well as keeping the inside mechanism in complete running order.
If you have a mechanical watch, it is best to wind it at the same time every day. This is extremely beneficial for the mechanism. You may want to make it a routine, winding it every morning when you wake up. If your watch has a day/date function, avoid setting the day and/or date at night. The day-date mechanism is activated during the nighttime hours and could be disrupted if set at this time.
What is the difference between a Mechanical Movement and an Automatic movement?
A mechanical movement is a movement based on a mainspring which when wound slowly unwinds the spring in an even motion to provide accurate timekeeping. As opposed to a manual mechanical watch which needs to be wound on a consistent basis, an automatic mechanical requires no winding because of the rotor, which winds the mainspring every time you move your wrist (see our section on automatic watch maintenance for more details).

Watch Movements

The movement of a watch refers to the mechanics that power the ticking of the timepiece, and there are two main choices when it comes to analog watches (watches with hour hands and are not digital), quartz or automatic.
What you choose really comes down to what you're looking for in a watch. There are many ways to look at what's attractive about both types of watches, but one way to look at it is the quartz watch as more practical and the automatic watch as more emotional.

Quartz

The majority of watches made today utilize the vibrations of a tiny quartz crystal to maintain timing, with the power coming from a battery that needs to be replaced every 2 to 3 years. Watches with quartz movements are more accurate, losing about a minute of accuracy over a year, and they can have either analog or digital displays, or both.

Solar
Some quartz watches are solar-powered, storing light that enters through the dial face, which eliminates visits to the jeweler to change the battery.

Atomic
Atomic watches can be calibrated daily (or several times a day) via radio signals from an atomic clock (such as the one located in Fort Collins, Colorado). Atomic time is measured through vibrations of atoms in a metal isotope that resembles mercury. The result is an extremely accurate time that can be measured on instruments. Radio waves transmit this exact time throughout North America, enabling some atomic watches to correct themselves to the exact time.

Choosing your watches Style

Selecting a watch that you or someone else will use and enjoy for many years to come can be a fun and easy process with a little bit of knowledge. If you’re not sure what kind of watch to buy and what kind of functions it should have, consider the following.
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Choosing Your Style

More than just something you wrap around your wrist to help keep you punctual, a watch can help punctuate your personal style, as well. The first thing to ask yourself is, when and how will I be wearing this watch? In the end, a watch is a reflection of you and your lifestyle, just like the clothes you wear or the car you drive.
The watch that you select should be appropriate for the activities for which you intend to use it. If your primary purpose is athletic, you might consider watches that are shock-proof. If you will be using the watch for work and play, do you need water-resistance, and if so, to what degree? If you will be using the watch for swimming and diving, you might want to consider a watch that has a screw-down crown or a plastic strap.
You'll also want to consider how much you want to spend on a timepiece. The $50 to $200 range brings durability as well as accuracy and stylistic flourishes. You'll find some models sporting chronographs and other multifunction cimplications, as well as some with gold-plated stainless steel cases and bracelets. In the $200 to $500 range, style gets ramped up, often with more sophisticated movements, diamond accents, or solid gold cases and bracelets.
When shopping for a timepiece, whatever the price or style, the brand name can play an important part in determining the right watch for you. Brand choice can be very subjective and will vary from person to person. Ultimately, it comes down to how you perceive a brand and what it represents, as well as what speaks to your sensibilities - high style or horological history, modern or traditional, collectible or affordable.

Casual Watches
Choose a casual watch that fits your personality and lifestyle. Think about the colors you wear the most and try to match them to the watch.
The watch face should be comfortable and easy to read. Look for watch features such as a second’s hand or date window that are useful to you.
Choose a comfortable band material. Keep in mind that leather is typically lighter weight with a closer fit, but is not water-resistant. A metal bracelet is usually heavier, water-resistant, and more durable. A rubber band typically has a casual look and is water-resistant.
See casual watches from Kenneth Cole, Nautica, Swiss Legend, Tommy Hilfiger, and more.

Dress Watches
Think thin if you want the watch to fit under your sleeves, or think bigger if you want to stand out.
Both men and women can add diamond or gemstone accents for formal occasions.
Metal bracelet bands are usually preferable, but fine leather shouldn't be overlooked.
See dress watches from AK Anne Klein, Bulova, Citizen, Seiko, and more.

Sport Watches
Look for a sport watch that is easy to read, such as a digital watch. The case of the watch is typically larger to house the timer, alarm, and other features found in sport watches.
Choose a water-resistance level appropriate for your needs. For instance, scuba divers should look for a minimum rating of 200 meters.
On analog watches, look for a rotating bezel to aid in timing specific events. For serious runners and bikers, a digital watch provides a wider range of timing features.
Watch band material should be based on personal preference and type of sport. The most popular material for sport watches is plastic or rubber.
See sport watches from Armitron, Casio, Puma, REACTOR, Timex, and more.

Fashion Watches
If you're in the market for a fashion watch, the rules go out the window. A great way to update your look or accentuate an outfit, fashion watches can be a rather personal choice.
Look for a watch that speaks to your artistic sensibilities, or can be thought of as an extension of your personality. Today, oversized and chunky watch cases are in, with some men's watches measuring well over 50 millimeters (2 inches) wide. To try out a new trend, try playing with your accessories. Not everyone can wear the hottest color in clothing, but everyone can wear it in a watch. Don’t be afraid to try different styles and colors in your watches. Now is the time to be fashionable.
See fashion watches from GUESS, Ed Hardy, Invicta, Swatch, TechnoMarine, and more.

Luxury Watches
With high-end luxury watches from Cartier, Omega, Movado, and TAG Heuer, you're paying for the finest materials, expert craftsmanship, and exclusivity (fewer numbers are manufactured for individual models). A fine watch is a wonderful heirloom to pass down from one generation to the next.
Consider one with automatic movement and a skeletonized dial or exhibition case back which displays the craftsmanship of the watchmaker. While fine watches are made all over the world today, Swiss watches still enjoy the highest reputation due to the wealth of knowledge and infrastructure built up in the Swiss watch industry over centuries. Keep in mind that a watch can only be given the coveted Swiss Made label if its movement is made, assembled, and inspected in Switzerland. A watch may have Swiss movement if the automatic movement was made in Switzerland and the watch was subsequently assembled elsewhere.
See luxury watches from Cartier, GUCCI, Movado, Omega, TAG Heuer, and more.

Parts of Watches

How Watches Work

In addition to their exterior beauty, watches are also an incredible feat of engineering and craftsmanship. This section contains an overview of the major parts of a watch, as well as an explanation of how watches operate.
Many complicated parts must all work in tandem in order to not only tell time, but perform a myriad of other functions. These could include a chronograph, altimeter, alarm, day/date calendar, moon phase, and slide rule bezel. Below are descriptions of the major internal and external parts and their functions. For more detailed explanations, visit our watch glossary.

External Watch Parts
Crystal
The crystal is the cover over the watch face. Three types of crystals are commonly found in watches. Acrylic crystal is an inexpensive plastic that allows shallow scratches to be buffed out. Mineral crystal is composed of several elements that are heat-treated to create an unusual hardness that aids in resisting scratches. Sapphire crystal is the most expensive and durable, approximately three times harder than mineral crystals, and 20 times harder than acrylic crystals.
Hands
A watch's hands are the pointing devices anchored at the center and circling around the dial, indicating hours, minutes, seconds, and any other special features of the watch. There are many different types of hands.
Alpha: A hand that is slightly tapered
Baton: A narrow hand, sometimes referred to as a 'stick hand'
Dauphine: A wide, tapered hand with a facet at the center, running the length of the hand
Skeleton: Cutout hands showing only the frame
Luminous: Hand-made of skeleton form, the opening filled with a luminous material
Bezel
The bezel is the surface ring on a watch that surrounds and holds the crystal in place. A rotating ratchet bezel moves in some sport watches as part of the timing device. If rotating bezels are bi-directional (able to move clockwise or counter clockwise), they can assist in calculations for elapsed times.
Crown
The crown is the nodule extending from the watch case that is used to set the time, date, etc. Most pull out to set the time. Many water-resistant watches have crowns that screw down for a better water-tight seal.
Dial
The dial is the watch face that contains the numerals, indices, or surface design. While these parts are usually applied, some may be printed on. Sub-dials are smaller dials set into the main face of the watch. These can be used for added functions, such as elapsed times and dates.
Watch Case
The watch case is the metal housing that contains the internal parts of a watch. Stainless steel is the most typical metal used, but titanium, gold, silver and platinum are also used. Less expensive watches are usually made of brass that has been plated with gold or silver.
Bracelet
A bracelet is the flexible metal band consisting of assembled links, usually in the same style as the watch case. Detachable links are used to change the length of the bracelet. Bracelets can be made of stainless steel, sterling silver, gold, or a combination.
Strap
A strap is simply a watchband made of leather, plastic, or fabric.


Internal Watch Parts
A watch’s movement is its main timekeeping mechanism. Today’s watch movements fall into two categories, automatic mechanical or quartz. Automatic mechanical movements mark the passage of time by a series of gear mechanisms. Most automatic movements are wound by the normal, everyday movement of your wrist, which charges the watch’s winding reserve. Quartz movements are powered by a battery and do not stop working once removed from your wrist.
Balance Wheel
The balance wheel is the regulating organ of a watch with a mechanical movement that vibrates on a spiral hairspring. Lengthening or shortening the balance spring makes the balance wheel go faster or slower to advance or retard the watch. The travel of the balance wheel from one extreme to the other and back again is called oscillation.
Gear Train
This series of small gears in both quartz and mechanical movement watches is responsible for transmitting the power from the battery (in a quartz watch) or spring (in a mechanical watch) to the escapement, which distributes the impulses that mark the time.
Escapement
This part of the watch restricts the electrical or mechanical impulses of the gear train, metering out the passage of time into equal, regular parts.
Motion Work
The motion work is a series of parts inside a watch that receive power from the escapement and gear train, which distribute and generate the watch’s power. The motion work is responsible for actually turning the watch’s hands.
Mainspring
The mainspring is the energy source responsible for powering the watch movement (as opposed to a battery in a watch with a quartz crystal movement). The spring is wound, either manually (using the winding stem) or automatically, by the motion of the wearer’s wrist. Potential energy is stored in the coiled spring, then released to the gear train which transmits the power to the escapement and motion work, which turns the hands on the watch dial.
Putting it all together
Watches essentially tell time by the integration of three main components, an energy source, a time regulating mechanism, and a display. The energy source can be electronic (as in a battery) or mechanical (as in a wound spring). A watch’s main timekeeping mechanism is called its movement.
Today’s watches fall into two categories, mechanical movements and quartz movements. Here’s a breakdown of how each type of movement works:
Mechanical (Automatic) Watches
Mechanical watches are made up of about 130 parts that work together to tell time. Automatic mechanical movements mark the passage of time by a series of gear mechanisms, and are wound by the movement of your wrist as you wear it. The gear train then transmits the power to the escapement, which distributes the impulses, turning the balance wheel. The balance wheel is the time regulating organ of a mechanical watch, which vibrates on a spiral hairspring. Lengthening or shortening the balance spring makes the balance wheel go faster or slower to advance or retard the watch. The travel of the balance wheel from one extreme to the other and back again is called oscillation. A series of gears, called the motion work, then turns the hands on the watch face, or dial. See illustration below.
Quartz Crystal Watches
Quartz watches work with a series of electronic components, all fitting together in a tiny space. Rather than a wound spring, a quartz watch relies on a battery for its energy. The battery sends electrical energy to a rotor to produce an electrical current. The current passes through a magnetic coil to a quartz crystal, which vibrates at a very high frequency (32,768 times a second), providing highly accurate timekeeping. These impulses are passed through a stepping motor that turns the electrical energy into the mechanical energy needed to turn the gear train. The gear train turns the motion work, which actually moves the hands on the watch dial.