Daniel Hart · ·
A watch that runs slow is a different problem from one that runs fast, and confusing the two sends people to the wrong fix.
Gaining is usually magnetism and costs nothing to correct. Losing is usually energy or wear, and it usually costs something.
Work through these in order, because the free explanations come first.
The short answer
Start with the free explanation
If the watch is automatic and you wear it for only a few hours a day, it is probably never reaching a full wind. A mainspring delivers its strongest, steadiest force when fully wound and its weakest at the end, and a balance receiving less energy swings less far and keeps worse time.
Wind it by hand to a full wind, wear it normally for two days, and measure again. A great many complaints about accuracy end here. Our accuracy calculator gives you a real figure rather than an impression.
The same logic applies to a watch left in a drawer between wears. Our guide to how long an automatic runs covers the reserve involved.
If it is fully wound and still losing
Then it is the movement. Watch lubricants thin, migrate and eventually dry out, and a movement running on degraded oil loses amplitude and therefore time.
Losing more than about fifteen seconds a day on a fully wound watch is a service, not a regulation. A regulation adjusts the rate on a timing machine and cannot fix a movement that is short of energy.
A tired mainspring is the other common cause on an older watch, and it is replaced during a service rather than separately.
| Symptom | Most likely cause | What it costs |
|---|---|---|
| Loses a few seconds a day | Normal for a mechanical watch | Nothing |
| Loses only on days you barely wear it | Not reaching a full wind | Nothing, wind it |
| Loses 15+ seconds a day, fully wound | Degraded lubricants or a tired mainspring | A service |
| Suddenly gains minutes a day | Magnetism, not this article | Usually nothing |
| Quartz losing seconds a day | The battery is near the end | A battery |
If it is quartz
A quartz watch should drift by seconds per month, not per day. Losing seconds a day means the cell is close to exhausted, and many movements deliberately slow before they stop.
Replace the battery before assuming anything is wrong, and have the gaskets checked while the case is open. Our guide to what a dive watch needs covers why an opened case should be treated as unsealed until it is pressure tested.
Our quartz and mechanical explainer covers what normal looks like for each type, which is the reference point this whole question depends on.
What is actually normal
Ten seconds a day either way is ordinary for a mechanical watch. Chronometer certification, whose criteria are published on the COSC site, only requires an average daily rate between minus four and plus six seconds, and that is a tight standard rather than a typical one.
Measure over several days in the position you actually wear it, because a single overnight reading is mostly measurement error, and rate changes with position. Our running fast diagnostic covers the opposite symptom and separates magnetism from a genuine fault.
If the watch is a common calibre, the expected figures are documented. Our NH35 explainer and ETA 2824-2 explainer cover two of the most widely used.
Frequently asked questions
Why is my automatic watch losing time?
Most often because it is never reaching a full wind. A mainspring delivers less force as it unwinds, and a balance receiving less energy keeps worse time. Wind it fully by hand and measure again over two days.
How much time loss is normal?
Around ten seconds a day either way is ordinary for a mechanical watch. Chronometer certification requires minus four to plus six seconds, which is a tight standard rather than a typical one.
Does my watch need a service or a regulation?
A regulation adjusts the rate and cannot fix a movement short of energy. Losing more than about fifteen seconds a day on a fully wound watch points at a service.
Why is my quartz watch losing seconds a day?
The battery is near the end of its life. Many quartz movements deliberately slow before stopping. Replace the cell and have the gaskets checked while the case is open.
Is losing time the same problem as gaining time?
No, and the difference is useful. Sudden gaining is usually magnetism and costs almost nothing to fix. Losing is usually energy or wear and usually costs something.
The verdict
Losing time is the less alarming of the two accuracy faults and the more likely to cost money, because it points at the movement rather than at a magnetic field.
Wind it fully and measure again before booking anything. That single step explains a large share of these complaints and costs nothing.
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.
