Why Is My Automatic Watch Running Fast or Slow?

You glance at your automatic watch, then your phone, and the two don't agree. A few minutes off after a week. Is something wrong — or is that just how mechanical watches are? The honest answer is: a little drift is completely normal, and a lot of drift is your watch asking for attention. Here's how to tell which one you've got.

First: what's "normal" for a mechanical watch?

A mechanical (automatic or hand-wound) watch is a tiny machine, not a quartz chip. It will never be perfectly accurate, and it isn't supposed to be. Accuracy is measured in seconds per day, and a healthy watch typically runs somewhere in the range of −10 to +20 seconds a day depending on the movement and how it's been regulated. A nicely-tuned watch might hold a few seconds a day; a chronometer-certified one, tighter still.

So if your watch is off by a couple of minutes after a week, do the math: a minute or two over seven days is only a handful of seconds per day. That's normal. It's the machine, not a malfunction.

The trouble starts when the drift is bigger, suddenly worse than it used to be, or wildly inconsistent.

Why a watch runs FAST

Running fast (gaining time) usually comes down to a few culprits:

Magnetism. This is the #1 cause, and the most overlooked. Phones, speakers, laptops, tablet covers, fridge doors, handbag clasps — all have magnets. A magnetized hairspring sticks to itself and makes the watch run dramatically fast (sometimes minutes a day). The good news: it's usually a quick, cheap fix — a watchmaker "demagnetizes" it in seconds.
Positional variance. A mechanical watch runs at slightly different rates depending on its position (dial up, crown down, etc.). If you leave it sitting in a position it happens to gain in, it'll read fast.
Over-amplitude or a regulation issue — less common, and a watchmaker's job to diagnose.

If your watch suddenly started gaining time, suspect magnetism first. It's astonishingly common.

Why a watch runs SLOW

Running slow (losing time) tends to point at different things:

Low power / not enough wear. An automatic winds from your wrist motion. If you don't wear it enough, or you're sedentary, the mainspring runs down and the watch loses amplitude — and time. A desk-bound day or two can do it.
It needs winding to start. An automatic that's stopped or low needs a manual wind (or a good amount of wrist time) to get back to full power.
Old, dried-out lubrication. This is the big one. Over years, the oils inside a movement degrade and thicken. The watch fights more friction, loses amplitude, and runs slow and erratic. Losing time that keeps getting worse is the classic sign a watch is overdue for service.
Wear or a developing fault — a watchmaker will spot it on a timing machine.

The simple at-home checks

Before you panic (or pay anyone):

Make sure it's fully wound. Take it off, give an automatic ~30 manual winds (or wear it actively for a day), then check it against a reference over 24 hours.
Keep it away from magnets for a day — off the phone, off the speaker — and re-check. If "fast" improves, you found your culprit.
Note the actual rate. Set it precisely to a phone/atomic clock, wait 24 hours, and measure the difference in seconds. That number — not "it feels off" — is what tells the story.

When it's time to see a watchmaker

Book a service when you see:

Losing time that's getting progressively worse (dried lubricant — the watch is wearing itself).
Drift that's way outside the normal range (e.g., gaining/losing many minutes a day) and isn't fixed by demagnetizing.
The watch stops even though it's being worn, or won't hold a charge.
It's simply been a long time. (See how often you should service a mechanical watch.)

A watchmaker checks the timing on a machine, measures the rate and amplitude in multiple positions, and tells you exactly what's happening — and a good one will document those before-and-after timing numbers as part of the service record.

A watch's rate isn't just trivia — it's a vital sign. Tracking it over time is how you catch a problem early instead of after a part wears out.

Keep a record of how your watch keeps time

Here's a habit that pays off: note your watch's rate over time. A piece that's drifting further every few months is telling you something before it stops. And when you do have it serviced, the timing numbers (rate before/after, amplitude, beat error) belong on the watch's permanent record — they're proof the work was done and the watch left the bench running right.

That's exactly what the service passport in Tick Tock Tracker captures: signed, dated timing results that become part of a watch's verifiable history. It turns "it feels a little fast" into an actual track record — better for you now, and better for the watch's value and provenance later.

Start tracking your watches — and their timing — free.