Watch accuracy : how to read the results?

So you have just measured your watch accuracy and you would like to know if everything is okay. Seems legit! 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 loose 1 minute every three days. Basically, each week; your watch will be 2 minutes and 20 second behind the « real » time. Not so good.

Those numbers look big. Let’s put some perspective. As there are 86 400 seconds composing every single day, loosing 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.

Watch accuracy : what to aim for?

Obviously, we all want our lovely mechanical watches to be absolutely accurate! 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 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 watch’s movement, if it has been correctly regulated by your watchmaker, if it is brand new or 50 years old and if you are taking good care of it with regular servicing or by following those tips.

Watch accuracy : 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 watchmakers have a tolerance range for each of their calibers and watches sold should stay in between that range. If you are not sure, contact directly your watchmaker. 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.

As a lot of 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!

Toolwatch app watch geek

Watch accuracy : what about the certificates?

We have already written an article on the different certifications in watchmaking. The three main one are the COSC (Chronometer) with -4 spd / + 6 spd, the Rolex Superlative Chronometer with -2 spd / +2 spd and the METAS ranging from 0 to +5 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?

See you soon for a next article to share our love for mechanical watches !