The Complete Beginner's Guide to Watch Movements: Understanding What Makes Your Mechanical Watch Tick

TL;DR: Watch movements come in three main types—manual mechanical (hand-wound, most traditional), automatic (self-winding via wrist motion), and quartz (battery-powered, most accurate). The major movement manufacturers are ETA, Sellita, Seiko, and Miyota. For most beginners, an automatic watch with an ETA or Sellita movement offers the best balance of reliability, serviceability, and value. In-house movements matter less than marketing suggests—focus on the specific calibre's track record, not just brand prestige.

 It took centuries of engineering for you to be able to wear that watch on your wrist. The movement inside is the engine that brings every function to life, and understanding how it works transforms you from a casual wearer into a informed wearer. This beginners guide to watch movements will walk you through everything you need to know, from the fundamental principles to the major movement manufacturers shaping the watch industry today. Whether you're considering buying a mechanical watch for the first time or simply want to understand what powers your current watch collection, this guide will give you the knowledge to appreciate these feats of engineering on a deeper level.

What Exactly Is a Watch Movement and Why Does It Matter?

The watch movement—sometimes called the calibre—is the internal mechanism that powers your watch and drives all its functions. Think of it as the heart of your timepiece, responsible for measuring time and moving the hands across the watch dial. Without a functioning movement inside the watch, you simply have an expensive bracelet.

Understanding watch movement types matters because the movement determines a watch's accuracy, longevity, service requirements, and price. When examining photos of the movement through a exhibition caseback, you're looking at the true character of any watch—the craftsmanship that makes the watch worth owning.

The movement also affects how you'll interact with your watch daily. Some movements need to be wound regularly, others run on batteries, and some harvest energy from your wrist movements. Knowing what powers your watch helps you provide proper care and set realistic expectations for performance.

What Are the Three Main Types of Watch Movements?

There are three main types of watch movements you'll encounter: mechanical, automatic, and quartz. Each operates on fundamentally different principles, and understanding these differences is essential for any watch enthusiast navigating the watch world.

Mechanical movements are the oldest type of movement, dating back to the pocket watch era. They store energy in a coiled mainspring that you wind by hand, releasing that energy slowly through a series of gears to power the watch. The escapement regulates this energy release, creating the distinctive ticking sound and sweeping second hand motion.

Automatic movements evolved from mechanical designs, adding a rotor—a weighted semicircular piece that spins with your wrist movements to wind the mainspring automatically. This automatic winding system means you don't need to wind the watch manually as long as you wear it regularly. Quartz movements, introduced in the 1970s, took the world by storm. They work differently to mechanical movements: a battery sends electricity through a quartz crystal, making it vibrate exactly 32,768 times per second, which is then divided down electronically to drive the hands (or digital display) with exceptional accuracy.

Quick Comparison Table: Movement Types at a Glance

This table answers about 80% of beginner questions in under 30 seconds. The "soul factor" is subjective, of course—but it captures why watch enthusiasts gravitate toward mechanical and quartz debates despite quartz technology being more accurate.

How Does a Mechanical Watch Movement Actually Work?

A mechanical watch movement operates through an ingenious system of springs, gears, and regulators working in harmony. When you wind the watch, you're tightening the mainspring, storing potential energy that will power the watch for its entire power reserve—typically 40 to 80 hours depending on the movement.

As the mainspring slowly unwinds, it transfers energy through a gear train that reduces speed while increasing torque. This energy eventually reaches the escapement, which acts as a metering device, releasing energy in precisely measured increments. The escapement works in conjunction with the balance wheel, which oscillates back and forth multiple times per second—typically beating at 28,800 times per hour in modern movements.

This produces accuracy measured in seconds per day rather than the fractions of a second you'd see with quartz watch movements. While less accurate than their electronic counterparts, mechanical movements offer something quartz cannot: a living, breathing machine on your wrist powered entirely by human ingenuity and physics. The reliability of a well-made mechanical movement, when properly serviced, can span generations.

Real-world example: The Furlan Marri automatic three-hand (grey market ~£400–550) is a true independent Geneva microbrand that uses a decorated Miyota 9039 with custom rotor and delivers sector-dial finishing that rivals watches costing triple the price.

What Is the Difference Between Automatic and Manual Movements?

The distinction between automatic and manual movements comes down to how energy enters the system. Both are fundamentally mechanical, but their winding mechanisms differ significantly, affecting how you'll interact with the watch.

Manual movements require you to wind the watch regularly—typically once daily—by turning the crown. This becomes a sort of ritual, and many enthusiasts appreciate this tactile engagement. Manual movements are often thinner because they don't require space for a rotor mechanism, making them popular in dress watches which demands a slim profile.

An automatic movement features the previously mentioned rotor that spins as you move your wrist throughout the day. This automatic caliber keeps the mainspring wound without conscious effort, provided you wear the watch regularly. If your watch stops because you've left it unworn for a few days, you'll need to wind the watch manually to restart it before the automatic winding takes over. Most modern automatic movements include manual winding capability for this reason.

Real-world examples: For manual-wind pieces, the Nivada Grenchen Antarctic 35mm (independent Swiss brand, around £700-800) offers a proper hand-wound Landeron 21 with 36-hour power reserve. For automatics, the Furlan Marri 2116-A three-hand (Geneva independent, around £1,000-1,100 new / £900-1,200 grey) delivers superbly finished La Joux-Perret G100 reliability at a competitive price point.

The Four Companies That Power 80% of All Watches

The watch industry relies on a handful of watch movement manufacturers who supply to brands worldwide. Understanding these suppliers helps you evaluate any watch beyond its brand name, revealing the engineering inside.

ETA, owned by the Swatch Group, has been the dominant swiss movement manufacturer for decades. An ETA movement powers countless Swiss watches across all price points, from entry-level pieces to luxury brands. The ETA 2824 automatic caliber, for instance, has earned legendary status for its combination of reliability and serviceability. Sellita emerged as a major alternative when ETA restricted supply to non-Swatch brands, and Sellita movements—like the SW200—are now found in numerous respected timepieces.

Beyond Switzerland, Seiko operates as both a watch brand and movement manufacturer, producing Seiko movements that range from affordable workhorses to the exceptional Grand Seiko calibres. Miyota, owned by Citizen, produces movements known for the best value, powering countless affordable watches. Japanese watch movements from both Seiko and Miyota have earned respect for their durability and accuracy, challenging the notion that only Swiss-made means quality.

Real-world examples: The Christopher Ward C63 Sealander (around £700-900) uses Sellita SW200 movements with excellent finishing. For Miyota-powered options, the Orient Bambino (around £150-250) offers remarkable value with an in-house Miyota-derived calibre.

Why Do Some Brands Develop In-House Movements?

An in-house movement—one designed and manufactured by the watch company selling the finished product—represents significant investment and engineering capability. Rather than purchasing from a third-party movement manufacturer, these brands produce movements within their own facilities, controlling every aspect of production.

Developing in-house calibres requires substantial resources: research and development, specialized machinery, skilled watchmakers, years of refinement and a lot of money. Brands like Rolex, Patek Philippe, and Jaeger-LeCoultre have produced their own movements for generations, while others like Tudor and TAG Heuer have more recently transitioned to in-house production for their premium lines.

For consumers, in-house movements can mean several things. They often indicate a brand's commitment to watchmaking rather than merely assembling purchased components. However, in-house doesn't automatically mean superior—a well-finished ETA movement can outperform a poorly executed proprietary calibre. When evaluating any luxury watch, consider the new movement's track record, service availability, and the brand's long-term commitment to supporting their calibres.

Real-world examples: The Tudor Black Bay 58 (around £3,500-4,000) represents excellent entry-level in-house territory with Tudor's MT5402 calibre offering 70-hour power reserve and COSC certification. For those with larger budgets, the Omega Seamaster 300M (around £5,000-6,000) showcases Omega's co-axial in-house movement technology. 

Buying a new watch with a brand-new in-house movement is like buying a new car with a brand-new engine: it might be groundbreaking, but it has no long-term track record yet, while an ETA or Sellita is the proven Toyota engine that any mechanic can service for decades.

What Should You Know About ETA and Sellita Movements?

ETA has shaped modern watchmaking more than perhaps any other manufacturer. Their movements power everything from fashion watches to serious tool watches, offering reliability across decades of production. The ETA 2892 automatic movement, for instance, serves as the base for numerous chronograph modules and complications due to its thin profile and robust construction.

Sellita entered the spotlight as ETA began restricting movement sales to non-Swatch Group brands. The company reverse-engineered ETA designs, creating compatible alternatives that watchmakers could service using the same techniques and parts. Sellita movements like the SW200 and SW300 are functionally equivalent to their ETA counterparts, and many watch companies now use them interchangeably.

For practical purposes, both ETA and Sellita movements offer excellent serviceability—almost any qualified watchmaker can service these calibres, and parts remain widely available. This matters significantly for long-term ownership, as some proprietary movements require returning to the manufacturer for any service work, potentially resulting in longer wait times and higher costs.

Real-world examples: The Hamilton Khaki Field Automatic (around £550-700) uses ETA movements with Hamilton's extended 80-hour mainspring modification. The Certina DS Action Diver (around £600-800) offers Sellita-powered Swiss dive watch performance at a competitive price.

How Do Seiko and Miyota Compare to Swiss Movements?

The rivalry between Swiss and Japanese movement's dates back to the quartz crisis of the 1970s, when Seiko's quartz movements nearly destroyed the traditional Swiss watch industry. Today, both nations produce movements across all quality levels, and blanket statements about one being superior to the other miss the nuance entirely.

Seiko movements range from the affordable 4R and 6R series found in mid-range Seiko watches to the remarkable Spring Drive and Hi-Beat calibres in Grand Seiko. The higher-end Seiko calibres rival or exceed many Swiss movements in finishing and performance. Miyota movements, while generally positioned at lower price points, offer exceptional value—their 9-series movements, in particular, punch well above their weight in accuracy and longevity.

When comparing movements, consider the specific calibres rather than national origin. A high-end Miyota movement may outperform a basic Swiss movement, while a Grand Seiko calibre can challenge any Swiss manufacture. The best watch for your needs depends on the specific movement's characteristics, not flags or assumptions about national superiority.

Real-world examples: The Seiko Prospex SPB series (around £800-1,200) features the 6R35 movement with 70-hour power reserve. For budget-conscious buyers, the Seiko 5 Sports line (around £200-350) delivers Seiko's 4R36 calibre with day-date complication at remarkable value.

How to Spot a Good Movement When the Brand Won't Tell You

Here's a trick that 99% of beginner's guide articles miss, and it takes less than 60 seconds. When a watch brand is vague about what's inside the watch—using phrases like "Swiss movement" or "Japanese automatic" without specifics—you can almost always find the answer yourself.

Look up the exact reference number of the watch (usually found on the caseback or in listings), then search "[reference number] + movement" or "[reference number] + calibre" online. Nine times out of ten, you'll find forum posts, reviews, or specification sheets revealing exactly which movement powers that timepiece. Watch manufacturers may be coy in their marketing, but the watch world documents everything.

A watch company using quality ETA, Sellita, Seiko, or Miyota movements has nothing to hide—the vagueness usually indicates either a lesser-known movement or, occasionally, fashion watches using generic calibres. Armed with this knowledge, you can guide yourself to find the perfect watch rather than relying solely on brand marketing.

What Features Should You Consider When Evaluating a Watch Movement?

Several factors determine whether a movement suits your needs. Power reserve indicates how long the watch runs when fully wound—longer reserves mean you can leave the watch unworn for extended periods without it stopping. Most modern automatic movements offer 40-80 hours, though some exceed 100 hours.

Accuracy matters differently depending on your expectations. Chronometer-certified movements guarantee accuracy within -4/+6 seconds per day, while uncertified movements may vary more widely. For daily wear, even a watch running ten seconds per day rarely causes practical problems.

Service intervals and costs deserve consideration before purchase. A complex chronograph movement requires more extensive service than a simple time-only calibre. Similarly, some in-house movements can only be serviced by the manufacturer, potentially limiting your options and increasing costs. Understanding these factors helps you choose the perfect watch for your lifestyle and budget, ensuring your vintage watch, or any watch remains functional decades from now.

Real-world example: The Christopher Ward Twelve X offers COSC-certified accuracy with an impressive 120-hour power reserve via its in-house Calibre SH21 movement, representing strong value in the mid-range independent British watch segment.

How Can This Guide to Watch Movements Help You Build Your Collection?

Armed with knowledge, you can make smarter purchasing decisions and better appreciate what you already own. When browsing your next watch, look beyond marketing and brand prestige to understand what's actually inside the watch case. Request photos of the movement when buying online, and don't hesitate to ask sellers about calibre specifications.

This guide is ultimately about understanding value. Sometimes the best value comes from a reputable third-party movement like an ETA or Sellita, expertly cased and finished. Other times, an in-house movement from a dedicated manufacture represents better long-term ownership. Watch manufacturers make different choices for different reasons, and understanding those choices helps you align purchases with your priorities.

The watch world rewards curiosity. Whether you gravitate toward the sweeping seconds of mechanical or the accuracy of quartz, understanding movements transforms watch ownership from accessory wearing into genuine appreciation.

Key Takeaways: What to Remember About Watch Movements

• Movement is everything: The calibre inside determines accuracy, service needs, longevity, and value far more than brand names alone—it's the true heart of any timepiece.
• Three types dominate: Manual mechanical (hand-wound), automatic mechanical (self-winding via rotor), and quartz (battery-powered electronic) each serve different preferences and lifestyles.
• Four manufacturers matter most: ETA, Sellita, Seiko, and Miyota supply movements to hundreds of watch brands worldwide—knowing their reputations helps you evaluate any watch.
• In-house isn't automatically better: Proprietary movements represent brand investment but don't guarantee superior quality; evaluate each calibre on its own merits and service record.
• Origin matters less than specifics: Swiss and Japanese movements both offer excellent options across all price points; judge specific calibres rather than national origin.
• Consider the full ownership experience: Power reserve, accuracy, and service requirements all affect daily enjoyment and long-term costs.
• Serviceability protects your investment: Widely-used movements like ETA and Sellita can be serviced by most qualified watchmakers, while proprietary calibres may limit your options.
• Research reveals the truth: When brands won't specify movements, searching the reference number online almost always uncovers what's really inside the watch case.
• Knowledge equals confidence: Understanding movements helps you identify true value in a market where marketing often obscures mechanical substance—making you a smarter collector.