Daniel Hart ·
A mechanical watch that suddenly starts gaining minutes a day has almost certainly been magnetised, and demagnetising it takes under a minute and usually costs nothing. A service costs a great deal more, which is why it is worth knowing which one you actually need.
Set how far out your watch runs, answer three questions, and this tool will tell you what to ask for.
A mechanical watch that suddenly gains minutes a day is almost always magnetised, not broken, and demagnetising costs next to nothing. This tool separates that case from the ones that need a regulation or a service, so you know what to ask for before you hand the watch over.
As an Amazon Associate, Watch The Watch earns from qualifying purchases at no extra cost to you. Tool outputs are guidance, not a substitute for the manufacturer’s official specs.
Frequently asked
Why does a magnetised watch run fast rather than slow?
The hairspring is a fine spiral that regulates the balance. When it magnetises, adjacent coils attract and stick together, which shortens its effective length and makes the balance swing faster.
How much does demagnetising cost?
Usually nothing or very little. A watchmaker passes the watch through a demagnetising coil and withdraws it slowly, which takes under a minute.
What is normal accuracy for a mechanical watch?
Around ten seconds a day either way is ordinary. COSC chronometer certification requires an average of minus four to plus six seconds per day, which is a tight standard rather than a typical one.
Can a quartz watch be magnetised?
Not in the way that matters. There is no hairspring, so the classic running-fast fault does not occur. A quartz watch drifting seconds per day usually needs a battery or has a circuit fault.
What is the difference between a regulation and a service?
A regulation adjusts the rate on a timing machine and is quick and cheap. A service strips, cleans, re-oils and reassembles the whole movement, and costs many times more.
Daniel Hart is the editor of Watch The Watch. He researches and writes the site’s buying guides, brand comparisons, and explainers, focused on accessible, enthusiast-level watches — affordable automatics, divers, field and dress watches, everyday quartz, and the straps, winders and tools that go with them. The goal is practical, budget-aware advice that helps readers choose the right watch for their wrist and their budget. Recommendations draw on manufacturer specifications and the wider enthusiast community.
