Automatic Watch
An automatic watch is a mechanical watch that winds itself from the movement of your wrist. A rotor inside swings as you move and tightens the mainspring, so it needs no battery. Worn every day it keeps running; left off for a few days it stops and has to be rewound.
With an automatic watch, the wearer is the power source. A half-moon weight known as the rotor swings freely with every movement of the wrist, and as it turns it winds the mainspring coiled within the case. The energy held in that spring is what keeps the watch running, with no battery and, for the most part, no need to wind it by hand.
Power reserve and daily rhythm
Fully wound, a typical automatic holds around 40 hours of running time. In everyday use the pattern is straightforward:
- Worn daily: the rotor keeps topping it up, so it never stops
- Set aside on Friday: it may well have stopped by Monday morning
- Put back on: a few swings of the wrist set it winding once more
If you rotate through several pieces, it pays to understand power reserve before you settle on one.
Accuracy and servicing
Being mechanical, an automatic is less precise than a quartz watch. A typical automatic gains or loses roughly 5 to 15 seconds per day, and entry-level movements can run wider still, with the Seiko 5's 4R36 rated at -35 to +45 seconds per day. That is normal for a mechanical watch rather than a fault; only chronometer-grade movements hold to within a few seconds per day. Every few years it needs servicing to refresh the lubricants. Affordable everyday automatics include the Seiko 5 and the dive-style Orient Mako. You can explore the whole family in the Movement category, and for a first automatic our Best Japanese Watches guide is a sensible place to begin.
Related terms
Watches that show this
Frequently asked questions
How long does an automatic watch keep running once you take it off
A typical automatic holds around 40 hours of power reserve when fully wound. So a watch you set aside on Friday evening may have stopped by Monday morning. Worn regularly, the rotor keeps it topped up and it never stops.
Is an automatic watch as accurate as quartz
No, an automatic is less precise than quartz because it is a mechanical system. A typical automatic gains or loses roughly 5 to 15 seconds per day, and entry-level movements can run wider; that is normal rather than a fault. Only chronometer-grade movements hold to within a few seconds per day, so if absolute accuracy matters most to you, quartz is the better choice.
Does an automatic watch need servicing
Yes, it needs servicing every few years to refresh the lubricants and keep the movement in good order. Affordable everyday automatics such as the Seiko 5 and the dive-style Orient Mako are known for being low-maintenance and dependable.