Automatic Watch Accuracy: How Accurate Should It Be?

Accuracy becomes one of the main considerations when it comes to buying a timepiece. Therefore, determining what movement should you get comes first. On the other side, when it comes to mechanical timepieces, most people primarily put their love for craftsmanship in the first place. Regardless, it’s still important to have reasonable expectations. Therefore, we are going to break down automatic watch accuracy to see how accurate should your watch be.

Talking about accuracy is definitely a winning point for quartz watches. The reason why I talk about automatic watches’ accuracy is none other than trying to give an answer to those who are concerned. Some factors, such as temperature, gravity, and magnetic forces are what people are concerned about. 

Watch lovers with automatic watches also worry if their watch would run faster or slower depending on their wrist movement. Well, it is clear that the significant difference between mechanical and quartz watches is the inaccuracy in mechanical movement. However, I’ll try to show the factors behind this matter.  

How Automatic Watches Work

Prior to discussing how accurate an automatic watch is, knowing how this type of watch works is essential. In simple words, automatic watches can wind themselves “automatically” and, thus also known as self-winding watches. It gets the energy from the wearer’s wrist movement. Any movement on the wrist would wind the mainspring and, thus, it stores and delivers the energy. Therefore, as long as the wearer regularly uses the watch, it won’t stop moving. 

An automatic watch has a rotor that is half-circle shaped and made of heavy material, like gold or platinum. This part is essential for automatic watches for the self-winding process. Whenever there are movements on the wearer’s wrist, the rotor would swing back and forth. During that process, the mainspring stores energy that in turn moves the gears until the balance wheel. 

Read also: How Do Mechanical Watches Work? Scrutinizing The Inner Parts

How Accurate is an Automatic Watch?

Most watch brands have stated information about watch accuracy in the watch specification. By that means, the wearer could expect the watch would run accurately as the information stated as many watch brands state their commitment to accuracy. 

However, the idea of self-winding brings concern for the wearer of automatic watches. Technically said an automatic watch would insignificantly lose and gain time yet it often goes unnoticed. The standard and acceptable accuracy for a self-winding movement are +/-10 seconds per day but there are still more precise calibers out there although they would cost higher. However, if the watch gains or loses a certain amount of time significantly, it definitely needs a service. 

The number of complications in an automatic watch is also the biggest factor in talking about accuracy. Let’s talk about a watch with a chronograph, date window, and moon phase. Each of the complications needs detailed control, and additional parts and each of them would add complexity to a watch movement. In that way, it definitely will affect the accuracy of the watch. The more complicated the movement, the higher the possibility of a time deviation. Therefore, it would be quite hard for a watch with a complex movement to keep 100% accuracy over time. 

In another case, the number of oscillations in a balance wheel is also a great factor to determine the automatic watch’s accuracy. The standard amount is eight swings (each swing represents back-and-forth movement) in a second which means 4 oscillations. This number equals the frequency of 4Hz which is definitely far below the typical quartz movement that has a rate of 32,768Hz. And the truth is that the higher the frequency, the better a watch is to provide accuracy.     

The automatic watch’s accuracy is also determined by several factors, especially the physical force or external shock when the watch is worn in daily activities. The other factors are usually caused by temperature, gravity, and magnetism. Most parts of watches are made of metal and this material would swell in the heat and shrink in the cold. Thus, extreme temperature fluctuations would bring significant effects on the watches as they might cause the overall function of the watches to deviate. The standard rule measures that a watch should be kept within 9-38 °C.

Much exposure to a magnetic device would also bring bad influences on automatic watches accuracy. Nickel, iron, and cobalt are kinds of magnetic metals that can be frequently found in cell phones, tablets, hairdryers, stereo speakers, etc. In its true sense, putting watches too often near these devices could cause the time to deviate. Therefore, try to put your automatic watches away from strong magnetic sources to avoid any unwanted damage.

Read also: How Long Do Automatic Watches Last? A Brief and How to Care

How Does Gravity Affect Accuracy?

Gravity is also the best influencer for time deviation in the timekeeping mechanism of automatic watches. Although it is impossible to avoid gravity, there are some ways to make the watches less affected. The effect of gravity is greater when an automatic watch is put on during the night. When a watch stays in one position for too long, such as during the night, it would impact the balance wheel. The next that happens is that it starts losing or gaining pace and, thus, makes the watch less accurate. 

When it comes to automatic watches, wearing them frequently or even often on a daily basis would be the best way to keep good accuracy. Make sure to wear them safely and avoid any damage that could give serious impairment to the watch. Regular service is also an important factor to keep accuracy in a watch as it could prolong and recalibrate the accuracy.

Final verdict

Every type of watch movement always comes with ups and downs as well as automatic movement. Although every watch brands strive for accuracy in automatic watches, a perfect piece with accuracy is still a journey. Instead, the mechanical build of automatic watches is the main charm. After all, is not always about super-duper accuracy for all the time.

You might also like: 10 Best Automatic Watches Under $1000 For Everyone