So you have just measured your watch accuracy and you would like to know if everything is okay or if you should head to the watch repair. Read along to find out what to do!
Watch accuracy: what is it?
The accuracy of your watch is expressed in seconds per day. If your watch is running at +5 seconds per day (or +5 spd), this means that each day, your watch is gaining 5 seconds. Therefore, each 12 days, your watch will be 1 minute ahead of the « real » time.
On the opposite side, if your watch is running at -20 seconds per day, then, your watch will lose 1 minute every three days. Basically, each week; your watch will be 2 minutes and 20 second behind the « real » time. Not a good news.
Those numbers look big. Let’s put some perspective. As there are 86 400 seconds composing every single day, losing or gaining a few seconds each day isn’t that bad in terms of accuracy.
For example, -10 spd still represents an accuracy of 99.9884%. Not bad right? However, this little discrepancy, adding up each day may represent quite a gap in the end. We need to find balance.
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Watch accuracy: what to aim for?
Obviously, we all want our lovely mechanical watches to be showing the correct time! The best result would be a nice 0 spd with each measure. While most watchmakers are trying to get closer to that dream, we could consider that any result ranging from -10 spd to +10 spd would be okay if we have a pragmatic approach.
Therefore, a really good accurate watch should be somewhere between -5 spd to + 5 spd and an absolute amazing one between -2 spd to +2 spd. This of course depends on the quality of your mechanical watch’s movement, if it has been correctly regulated by your watchmaker, if it is a modern watch or 50 years old and if you are taking good care of it with regular servicing or by following those tips.
What you would like to avoid is variation in rate. As long as your watch is being regular whether it’s taking time or losing time, you can always having it adjusted. If your Swiss watch is alternately losing time or gaining time, then this might indicate that it is now time for a complete servicing.
So what should I do?
First of all, measure the accuracy of your watch regularly. You can use the Toolwatch website or our iPhone and Android app. Then, if you observe a bad result, check what should be expected with your watch. Most watch manufacturers have a tolerance range for each of their calibers and watches sold should stay in between that range.
If your watch is out of that range and still under warranty, then you can ask your watchmaker to regulate your watch to their tolerance for free.
If your accuracy is really bad, your watch might be magnetized. In that case we would recommend using a demagnetizer for watch. Magnetic fields and many other factors may disrupt the accuracy of your watch, make sure to check it regularly and to follow our best tips to keep your accuracy at its best!
What about the certificates?
We have already written an article on the different certifications in watchmaking. The three main one are the COSC (Chronometer Certification) with -4 spd / + 6 spd, the Rolex Superlative Chronometer with -2 spd / +2 spd and the METAS ranging from 0 to +5 spd. Grand Seiko Spring Drive movements have an accuracy of -1 spd / + 8 spd.
While certificates may assess other elements of the watch such as the water resistance or magnetic resistance, all certificates are there to guarantee a certain level of accuracy for mechanical watches.
Did you know? There are some small tips you can use so that you can regulate yourself your watch?
Also, even quartz movements have different level of accuracy, we recently had a look at the best quartz watches.