How to choose
Quartz, automatic or hand-wound: which watch you will still be wearing in year five
Three movements, three different jobs for the owner. What a chronometer mark certifies, what the water-resistance line permits, and the yearly running cost.
The movement is the only part of a watch that decides what you have to do to keep it running. Everything else — the case metal, the dial, the bracelet — changes how it looks and what it costs, but not whether it stops on a Tuesday because you left it in a drawer.
This guide takes the three movement types in the order that matters: what each one asks of the owner, what a chronometer certificate actually measures, what the water-resistance line on the dial permits, and what the whole thing costs to keep going for a year. Every price below is a stated example with the arithmetic shown, because no live price feed is connected to this site.
What each movement asks of the owner
A quartz watch runs from a battery and needs nothing from you until it stops. An automatic winds itself from the motion of your wrist and stops once its power reserve runs out, which is why a watch worn twice a month is a watch you reset twice a month. A hand-wound movement needs winding on a schedule you keep, usually at the same time each day, and the power reserve printed on the maker's own specification sheet tells you how much slack you have.
The running costs follow from that. Taking a stated example of a battery fitted for $15 every 3 years, a quartz watch costs about $5 a year to keep going. Taking an assumed 7-year service interval and an example $450 service — both figures are assumptions written here so the division can be checked, not quotes from any workshop — a mechanical watch costs about $64 a year. That is a factor of roughly 13 between the two, and it is the largest single difference in ownership cost between them.
What fails is different too. A quartz movement usually dies at the battery or at a leaking seal, and both are cheap. A mechanical movement loses amplitude as its lubricants age, which shows up as a rate that drifts further out each month before anything audibly breaks. The first is an event; the second is a slope, and the slope is why mechanical owners end up with a service bill they did not plan for.
| Movement | Owner's routine | Example service or battery | Example cost per year |
|---|---|---|---|
| Quartz | Nothing until it stops | Battery fitted every 3 years at $15 | about $5 |
| Automatic | Wear it regularly, or it stops when the power reserve runs out | Full service every 7 years at $450 | about $64 |
| Hand-wound | Wind it on a fixed schedule, usually daily | Full service every 7 years at $450 | about $64 |
The intervals and prices here are assumptions stated so the arithmetic can be checked: $15 divided by 3 years is $5 a year, and $450 divided by 7 years is about $64 a year. Replace both with the service price and interval the maker of the watch you are considering publishes, then use the cost-per-wear calculator on this site.
What a chronometer mark certifies, and what it does not
The Contrôle Officiel Suisse des Chronomètres tests movements, not finished watches, against the criteria of ISO 3159. A mechanical movement is run for 15 days in five positions — 6 o'clock, 3 o'clock, 9 o'clock, dial up and dial down — at three temperatures of 8, 23 and 38 degrees Celsius. To be certified as a chronometer, the average daily rate must fall between -4 and +6 seconds per day.
That band is 10 seconds wide, and the asymmetry matters. A certified watch sitting at the fast end of the band gains about 3 minutes over 30 days and roughly 36 minutes over 365 days, because 6 seconds a day multiplied by 365 is 2,190 seconds. A certified watch at the slow end loses about 24 minutes in the same year. Both are inside the certificate. If you reset a watch against a phone every Sunday, that spread is invisible; if you do not, it is the whole experience of owning the thing.
The certifier also runs a tighter grade, Excellence Chronometer Certified, in which the rate band narrows to -2 to +4 seconds per day and the test adds simulated wear, magnetic resistance up to 200 gauss and verification of the power reserve. Quartz movements are not tested against the full mechanical criteria: the certifier states that they are assessed against in-house specifications inspired by ISO 3159 and adapted to the instrument. A quartz watch with no certificate at all is still, in ordinary use, the more accurate object.
| Item tested | Chronometer Certified | Excellence Chronometer Certified |
|---|---|---|
| Testing period | 15 days | 15 days |
| Positions | 5: 6, 3 and 9 o'clock, dial up, dial down | The same five positions |
| Temperatures | 8, 23 and 38 degrees Celsius | 8, 23 and 38 degrees Celsius |
| Average daily rate permitted | -4 to +6 seconds per day | -2 to +4 seconds per day |
| Other criteria | The rate criteria of ISO 3159 | Those criteria plus simulated wear, magnetic resistance to 200 gauss and power reserve |
The certificate is issued to the movement before it is cased. A magnetised hairspring, a knock or a dry mainspring barrel can put a certified watch outside its own band later, which is why the mark describes the movement as it left the testing institute rather than the watch as it sits on your wrist.
The water-resistance line is a specification, not a mood
Manufacturers publish exactly what each marking permits, and the wording is narrower than most buyers assume. In Seiko's own published instructions for a current calibre, a watch with no marking at all should be kept away from drops of water and from sweat. A watch marked only WATER RESISTANT withstands accidental contact with water in everyday life, and the same page says plainly not to use it for swimming.
The swimming line starts at WATER RESISTANT 5 BAR, which the maker describes as suitable for sports such as swimming. WATER RESISTANT 10 BAR or 20 BAR is described as suitable for diving that does not use an air cylinder. Those four tiers cover almost every watch sold, and the difference between the second and the third is the difference between a watch you take off at the pool and one you do not.
Two practical points follow. The marking describes a new, correctly sealed watch, not one that has been opened for a battery, so a quartz watch that has had three battery changes has had its gasket disturbed three times. And the rating is a static pressure figure: pulling the crown out while the watch is wet defeats every tier on the list, whatever number is printed on the case back.
| Marking on the dial or case back | What the maker says it withstands |
|---|---|
| No marking at all | Avoid drops of water and sweat |
| WATER RESISTANT | Accidental contact with water in everyday life; not for swimming |
| WATER RESISTANT 5 BAR | Suitable for sports such as swimming |
| WATER RESISTANT 10 (20) BAR | Suitable for diving not using an air cylinder |
These wordings are taken from the published instructions for one current calibre. Another maker's manual may set out different tiers, so read the manual for the model in front of you rather than assuming the tiers are universal.
Fit, metal and the parts you will replace
The measurement that decides whether a watch is comfortable is not the case diameter printed in the listing but the lug-to-lug span, because that is what has to sit inside the flat part of your wrist. Measure your wrist across the flat, then check the lug-to-lug figure on the maker's specification page; a case that overhangs will roll, and no strap fixes it.
Strap width is the other number worth reading before you buy. A watch that takes a common width has a replacement market; an odd width or an integrated bracelet does not. On a stated example of a $40 leather strap replaced every 2 years, that line is $20 a year — four times the quartz battery line from the first table, and the cost most owners forget entirely.
If the case is described as gold, the mark on it is regulated. Under the FTC Jewelry Guides an alloy below 10 karat fineness may not be called gold at all, and a plated case marked Gold Filled must carry the karat fineness of the plating immediately before the term. A watch case described as gold with no karat designation anywhere on it, in a listing or on the case back, is a listing with something missing rather than a bargain.
- Measure the flat of your wrist and compare it with the maker's lug-to-lug figure, not the case diameter
- Check the strap width is a common size so replacements exist in 5 years' time
- Check whether a bracelet is sized by screws, pins or a friction system, because that decides whether you can adjust it at home
- Read the power reserve from the maker's specification page if the movement is mechanical
- Find the published service price and interval before buying, and put both into the cost-per-wear calculator
Which movement to buy, in one paragraph
If you will wear the watch most days and want it to be right without thinking, quartz wins on every number in this guide: about $5 a year against about $64, no winding routine, and better timekeeping than a certified mechanical movement is required to deliver. If you want the object rather than the readout, a mechanical movement is a reasonable thing to want, and the honest way to buy one is to accept the service line in the budget before you accept the price.
The hand-wound case is narrower than it looks. It suits someone who wears one watch daily and likes the ritual; it is the worst choice for a watch that will sit in a drawer between occasions, because every outing starts with resetting the date and the time. Match the movement to how often the watch will actually leave the drawer, and the other decisions get easier.
Before you buy
- Decide how many days a week the watch will actually be worn before comparing any two models
- Read the movement type and, if mechanical, the published power reserve from the maker's specification page
- Find the manufacturer's published service interval and price, and divide one by the other for a yearly figure
- Check the water-resistance marking against the maker's own definition rather than against the depth number
- Measure the flat of your wrist and compare it with the lug-to-lug span, not the case diameter
- Confirm the strap width is a common size so replacements will exist in five years
- If the case is described as gold, find the karat designation on the case or in the listing
Questions readers ask
- Is a chronometer certificate worth paying extra for?
- It buys a measured rate, not a guaranteed one. The certified band is -4 to +6 seconds per day, which allows about 3 minutes of drift over 30 days at the fast end. If you already reset the watch weekly, the certificate changes nothing you will notice. If you want evidence that the movement was individually tested over 15 days in five positions, it is the only widely published proof.
- How often does an automatic watch really need a service?
- The maker publishes an interval for each calibre, and that published figure is the one to budget against. This guide uses an assumed 7 years purely to show the division: a $450 service over 7 years is about $64 a year. Substitute the interval and price from the manufacturer's own service page and the arithmetic stays the same.
- Can I swim in a watch marked WATER RESISTANT?
- No. The manufacturer's own instructions say a watch marked WATER RESISTANT withstands accidental contact with water in everyday life and should not be used for swimming. The swimming tier starts at 5 BAR. The marking also assumes an undisturbed seal, so a watch that has been opened for battery changes is not guaranteed to still meet it.
- Does a quartz watch lose value faster than a mechanical one?
- Resale value depends on the model and the market rather than the movement type, and this site publishes no resale data because it has no price feed. What is certain is the running-cost side: about $5 a year for a battery against about $64 a year for a serviced mechanical movement, on the example figures used throughout this guide.
- What does 'gold' on a watch case legally have to mean?
- Under the FTC Jewelry Guides, an alloy below 10 karat fineness may not be described as gold. A plated case described as Gold Filled must have the karat fineness of the plating stated immediately before the term, with equal conspicuousness. A case described as gold with no karat figure anywhere is a listing missing a required element.
Sources
- Contrôle Officiel Suisse des Chronomètres — Chronometer Certified: 15 days, five positions, three temperatures, -4 to +6 seconds per day under ISO 3159 — checked 2026-11-03
- Seiko — published instructions for calibre 6L35, water resistance performance tiers — checked 2026-11-03
- 16 CFR Part 23 — Guides for the Jewelry, Precious Metals, and Pewter Industries (2026 edition, U.S. Government Publishing Office) — checked 2026-11-03
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