Chronograph Watches Explained: How to Read One, and How to Use It

A chronograph is a watch with a built-in stopwatch. That is the whole idea. The complexity people find intimidating is just the consequence of fitting a stopwatch onto a dial that is already telling the time.

It is the most popular complication in watchmaking and probably the least used. Most chronographs are bought for the symmetry of the sub-dials and never started. Which is a pity, because it takes about two minutes to learn and turns out to be genuinely handy — timing parking, a run, a phone call, how long the pasta has been on.

Reading the dial

A chronograph has two sets of indications that must not be confused: the ones that tell the time, and the ones that belong to the stopwatch.

Telling the time, you have the usual hour and minute hands. The running seconds often move to a small sub-dial, typically at 6 or 9 o'clock, so that the centre of the dial can be given over to the stopwatch.

The stopwatch consists of:

• A central chronograph seconds hand, usually the longest and often a different colour. At rest it sits at 12 and does not move. This is the giveaway that a watch is a chronograph rather than merely having sub-dials.
• A minutes counter, generally 30 minutes, sometimes 60.
• An hours counter on three-register designs, generally 12 hours.
• On some watches, a fractional-seconds counter — 1/10th or 1/20th of a second.

The Tissot T-Heritage 1973 is a clean example of a two-register layout: a central chronograph hand with 60-second and 30-minute sub-dials, plus 12 hours, a date at 6 o'clock and tachymeter markings around the outer rim.

The Bulova Lunar Pilot shows a three-register arrangement, and an unusual one: a 1/20th-second chronograph counter at 3 o'clock, running seconds at 6 and a 60-minute chronograph counter at 9.

Working the pushers

Two pushers, on the right-hand side of the case, above and below the crown.

Top pusher (2 o'clock): start and stop. Press to start timing, press again to stop and read.

Bottom pusher (4 o'clock): reset. Press once the chronograph is stopped and all counters fly back to zero.

The sequence is always start, stop, reset. The bottom pusher does nothing while the chronograph is running on a standard mechanical chronograph — do not force it.

Some movements add functions. ADD lets you restart from where you stopped, accumulating time across intervals; SPLIT lets you read an intermediate time while timing continues. The Tissot Seastar 1000 chronograph specifies both.

One rule that matters

Never operate the pushers under water, unless the watch is specifically designed for it. Chronograph pushers are the least well-sealed openings in the case. This holds even on a 300-metre chronograph — the rating describes a sealed, static case, not one with a pusher being pressed. Our water resistance guide covers why the ratings are more conditional than they look.

The tachymeter scale

That outer ring marked 400, 300, 200, 120, 90, 80 — usually on the bezel or the dial's outer edge — is a tachymeter. It converts elapsed seconds into units per hour, and it is simpler than it looks.

To measure speed over a known distance: start the chronograph, travel exactly one kilometre (or one mile), stop. Read the number the chronograph seconds hand points to on the tachymeter scale. That is your average speed in km/h (or mph). Thirty seconds for a kilometre reads 120 — 120 km/h.

To measure a rate of production: time one item. If it took 20 seconds, the scale reads 180 — 180 units per hour.

The scale works because it is simply 3600 divided by the elapsed seconds, pre-printed. It only functions for events between about 7 and 60 seconds, since beyond a minute the hand starts a second revolution.

You will find tachymeter scales on the T-Heritage 1973, the Lunar Pilot, and — as a fixed ceramic bezel — on the Tissot PRS 516.

Quartz or mechanical?

This is the decision that most affects both price and behaviour.

Quartz chronographs

More accurate, thinner, cheaper, and capable of timing fractions of a second that no mechanical chronograph can resolve.

The Casio Edifice EFB-710D is a 41mm quartz chronograph with a date, rated to 20 ATM — 200 metres. That combination of size, rating and price is difficult to argue with.

The Casio Edifice EFV-610EL offers the same idea on a leather strap at 43.5mm with 100 metres.

The Tissot Chrono XL is a 45mm × 11mm Swiss quartz chronograph with a sapphire crystal, 100 metres, a 1/10th-second counter and an end-of-life battery indicator, on an interchangeable textile strap.

The Bulova Icon 98B316 uses Bulova's proprietary eight-hand quartz movement at 262 kHz — eight times the frequency of a standard quartz movement — with a carbon-fibre-effect dial, screw-back case, screw-down crown, curved mineral crystal and 300 metres of water resistance.

That 262 kHz figure is worth dwelling on. Higher frequency means better accuracy, and it also allows the smooth, near-continuous sweep of a seconds hand that people associate with mechanical watches. It is genuinely a different class of quartz.

Mechanical chronographs

A mechanical chronograph is one of the more complicated things a watchmaker builds: a clutch, a column wheel or cam, and a reset mechanism, all fitted around a running movement. You pay for that.

The Tissot PRS 516 Powermatic 80 is a 42mm case in 316L steel with black PVD coating, a fixed ceramic tachymeter bezel, sapphire crystal, exhibition case back, 100 metres, and a Swiss automatic movement with up to 80 hours of reserve and a patented Nivachron balance spring for magnetic resistance.

The T-Heritage 1973 is a 43mm × 14.8mm Swiss automatic chronograph with a 60-hour reserve, sapphire crystal, exhibition case back and 100 metres.

The TAG Heuer Aquaracer Chronograph combines the complication with genuine dive capability: 43mm steel case, black ceramic unidirectional 60-minute bezel, screw-down crown, anti-reflective sapphire, 300 metres, and the Swiss automatic Calibre 16 driving 30-minute and 12-hour counters. It is ex-display stock — see what that means.

Note the thickness. The T-Heritage is 14.8mm; the chronographs are the thickest watches in most catalogues, because there is a whole extra mechanism in there. If a slim watch matters to you, read the dress watch guide instead.

Buying advice

Decide whether you will use it. If the honest answer is no, you are buying the aesthetic — in which case a quartz chronograph gives you the same look, thinner and cheaper, and you can spend the difference elsewhere.

Check the sub-dial layout is legible. Three registers on a busy dial at 40mm can be genuinely hard to read. Look at the actual photographs rather than the specification.

Look at thickness, not just diameter. Anything over about 14mm will catch on a cuff.

If it needs to get wet, check for a screw-down crown as well as the rating, and accept that the pushers stay untouched in water.

Watch out for the fake chronograph. Some watches have sub-dials that are day, date and 24-hour indicators rather than chronograph counters, and no pushers at all. If there are no pushers, it is not a chronograph.

Browse Tickmere's chronographs, or read the movements guide to weigh quartz against mechanical more broadly.

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