Every mechanical watch has a rate, a few seconds gained or lost each day, as personal to the movement as a fingerprint. These guides are about finding yours.
Start here
Why your watch runs fast or slow is the one to read first. The ordinary reasons a rate is what it is, the less ordinary ones, and what a number needs before it means anything at all.
Work out your own rate
The watch accuracy calculator turns two moments and an offset into seconds per day. Nothing to install and nothing to sign up for; it is the same arithmetic the app does, done once.
Understanding the number
- What seconds per day actually means. The unit, the sign, and what a given rate looks like after a week or a month.
- What is good accuracy for a mechanical watch. What the common reference bands allow, why most watches are specified far wider, and why a steady rate beats one that merely averages near zero.
Measuring it
- How to measure watch accuracy without a timegrapher. The method, what to hold steady, and the mistakes that spoil a reading.
- Timegrapher readings and real world rate. Why a service report and a week on the wrist can disagree with both being right.
What moves it
- Resting position and overnight accuracy. Why gravity changes the answer, and the one adjustment an owner can make safely.
- Power reserve, winding, and rate. Why a watch running down keeps different time, and how much wearing actually winds an automatic.
- Magnetism and mechanical watches. The sudden large gain, what causes it, and the second cause that looks exactly the same.
Over the years
- Servicing, and what the numbers do afterwards. Why recommended intervals run from about three years to about ten, and what a rate does as one comes due.
The support pages answer the most common questions about the app itself: runs, readings, resting positions, the accuracy bands, and how your data is stored.