Audemars Piguet Royal Oak 25654ST Review

THE FIRST LOOK

Audemars Piguet Royal Oak 25654ST First Impressions

What hits you the moment you pick up the steel Quantieme Perpetuel.

The Audemars Piguet Royal Oak 25654ST does not introduce itself. Lay it in a tray beside the modern steel complications in a case of Audemars Piguet watches and it is the smallest, flattest and quietest object there. Then you pick it up, and the trick becomes obvious. The case is 39mm across and sits somewhere between 8mm and 9mm tall depending on whose measurement you trust, which means this Audemars Piguet Royal Oak 25654ST is a full perpetual calendar that is thinner than most three-hand dress watches. Nothing built since has repeated that.

(image courtesy of Sotheby's)

The second impression is restraint. Four registers sit on a lightly textured silvered dial, slightly sunken so the surface has real depth, with blued steel hands in the subdials and applied baton markers holding the main track. There is no leap year window, no busy chapter ring, no attempt to justify the complication visually. The moon at six o'clock is small and precise rather than decorative. It reads like a calendar built by people who assumed you already knew what you had bought, which after forty years is still the most confident dial in the category.

THE WEARING EXPERIENCE

Audemars Piguet Royal Oak 25654ST On the Wrist

How a 39mm perpetual calendar actually wears, day in and day out.

The Audemars Piguet Royal Oak 25654ST wears exactly like a 39mm Royal Oak, which is to say slightly larger than the number suggests and considerably flatter than anything else with this complication. The integrated bracelet pushes the visual footprint out past the case, so the watch covers wrist real estate the way a 41mm watch would, while the roughly 46mm lug-to-lug span keeps everything inside the bones on a 6.25 inch wrist. Anything from 6.25 to 7.5 inches is comfortable territory. Below that, the bracelet taper starts to overwhelm.

Weight is where it separates from the modern references. A steel 25654ST is noticeably lighter than an Audemars Piguet Royal Oak 15202, because the case is thinner and the vintage bracelet links are finer, and the balance sits evenly rather than pulling to the caseback. It disappears under a cuff completely, which almost no perpetual calendar does. The compromise is adjustment. There is no micro-adjust and no half-link system, so sizing is a links-only exercise, and on a hot day you will feel the half link you do not have.

SHOP THIS WATCH

Shop the Audemars Piguet Royal Oak 25654ST

Browse authenticated Audemars Piguet Royal Oak watches available now at WatchGuys.

If a thin steel perpetual calendar with real scarcity behind it is what you are after, here is what we currently have available. Every watch is authenticated in house and backed by the WatchGuys 2 Year Warranty.

Buy Audemars Piguet Royal Oak 25654ST

BUILD QUALITY

Audemars Piguet Royal Oak 25654ST Specifications

Breaking down the steel Quantieme Perpetuel component by component.

Case and Bezel

The Audemars Piguet Royal Oak 25654ST case is a two-part steel sandwich compressed by eight white gold hexagonal screws that pass through the octagonal bezel and thread into the caseback, with a gasket trapped between them. The bezel is therefore not a separate component to evaluate. It is structural, and it is what holds the watch together. Brushed top surfaces meet polished bevels along the flanks in transitions that remain sharper on an untouched example than almost anything made today.

Thickness is the one figure nobody agrees on. Auction catalogs commonly publish about 8.25mm, while specialist dealers list 9.3mm, and the gap comes down to whether the crystal dome and caseback profile are included in the measurement. Either way it presents as genuinely thin. The screw-down crown is small and unfussy, the sapphire crystal is flat and clean, and the caseback is solid steel carrying the case number and serial. Water resistance was rated at roughly 20 metres when new, which on a case seal that is now around forty years old means splash protection at best. Treat it as a dry watch.

Dial

The Audemars Piguet Royal Oak 25654ST dial is the reason this reference still has a following. Early examples run a smooth or very lightly textured silvered surface rather than the deep tapisserie of the modern references, with four slightly recessed registers: month at twelve, day at nine, date at three, and the astronomical moon at six with its own age graduation. Applied baton indices and matching baton hands keep the main display clean, while blued steel hands in the subdials do the visual separation work that colour printing does on a modern calendar dial.

Two dial generations exist, commonly called Series C and Series D, separated by the Audemars Piguet signature typography that changed in the early 1990s. The earlier small-signature dials draw the stronger premium. Salmon, black and champagne dials trade far above the standard silvered version. What is not there matters just as much: there is no leap year indicator, because Caliber 2120/2800 does not have one, and there is no lume anywhere on the dial. Any listing that claims a leap year display on a 25654 is describing a different reference.

Bracelet and Clasp

The Audemars Piguet Royal Oak 25654ST bracelet is integrated, tapering, and finished with a signed steel deployant clasp, running around 147mm in total length on a full set. It articulates beautifully and lies flatter than a modern Royal Oak bracelet, but it is also the single biggest risk on the reference. Vintage AP links stretch, replacements are effectively unobtainable outside of donor watches, and because the bracelet is integrated there is no strap fallback if the stretch becomes uncomfortable. Buy the bracelet as carefully as you buy the case.

EXPERT TIP | Robertino Altieri | WatchGuys CEO

What to Check on a Pre-Owned Royal Oak 25654ST

"Four things, in order. One, hold the case flat and look down the flank: if the bevel between the brushed top and the polished side has gone soft, it has been polished and the value drops hard. Two, hang the bracelet vertically and watch for daylight between the links, because stretch is the repair nobody can fix on this reference. Three, match the dial signature to the serial range, since a small-signature dial on a late case is a swapped dial. Four, ask for an extract from the archives before you wire anything. On a watch this rare, an extract is not a nice extra, it is the transaction."

UNDER THE HOOD

Audemars Piguet Royal Oak 25654ST Movement Review

How the movement performs where it matters: on the wrist, every day.

The Audemars Piguet Royal Oak 25654ST runs Caliber 2120/2800, a 38 jewel automatic beating at 21,600vph with roughly 40 hours of reserve. The base is the 2120, Audemars Piguet's version of the Jaeger-LeCoultre 920 architecture developed in 1967, at 2.45mm the thinnest full-rotor self-winding movement ever put into series production. Add a 1.55mm calendar module and the whole thing still lands around 4mm, which is the entire reason this watch exists at this thickness. The finishing matches the ambition, with a gold rotor riding on four ruby rollers along a beryllium rail, though the solid caseback means you will never see it.

Living with it is a different conversation. Winding efficiency on the 2120 family is modest by modern standards, and the roughly 40 hour reserve was set when watches came off the wrist once a week, not once a night. Leave the 25654ST in a drawer over a long weekend and you will come back to a stopped watch and a full calendar reset. A serviced example should hold within a few seconds a day and the crown winds smoothly with almost no resistance, but treat that reserve as a design constraint, not a specification. A winder is not a luxury on this reference. It is the difference between wearing the watch and setting the watch. That architecture eventually gave way to the thicker, more robust in-house 3120 family found in later references like the Audemars Piguet Royal Oak 15400, which trades elegance for endurance.

EXPERT TIP | Robertino Altieri | WatchGuys CEO

Budget for the 2120/2800 Service Before You Buy

"A full service on a 2120/2800 is not a Rolex service. You are looking at several thousand dollars and a wait measured in months, not weeks, and calendar module parts for this generation are genuinely scarce. My rule with clients is simple: if the watch has no service paperwork inside the last five to seven years, price the service into your offer on day one. A cheap 25654ST with an unknown movement history is not a bargain, it is a deferred bill."

THE COMPLICATION

Setting the Audemars Piguet Royal Oak 25654ST Perpetual Calendar

What it actually takes to bring a stopped Quantieme Perpetuel back to life.

The Audemars Piguet Royal Oak 25654ST corrects its calendar through three recessed pushers set into the case flanks, two on the left side and one on the right, each operated with a setting pin rather than a fingertip. Advance the date first, then the day, then the month, and only ever between roughly three in the morning and nine at night, because outside that window the calendar wheels are already engaged and forcing them is how expensive damage happens. Because there is no leap year indicator, you have to know where in the four year cycle you are before you start, which usually means running the month wheel forward until the calendar lines up with reality.

None of that is difficult. It is simply slow, and it is the honest cost of a complication built when a perpetual calendar was expected to be a considered ritual rather than a convenience. Owners who wear the watch in rotation quickly learn to keep the original winding box or a modern winder in service. Owners who put it away for a month learn the setting sequence very well. Compared with a modern complicated Royal Oak such as the Audemars Piguet Royal Oak 26120, where everything is driven from the crown, the 25654ST asks more of you at every stage.

MARKET VALUE

Audemars Piguet Royal Oak 25654ST Price

What the steel Quantieme Perpetuel costs right now on the secondary market.

Audemars Piguet Royal Oak 25654ST pricing has the widest spread of any Royal Oak reference we track, and the range in the card above is real rather than cautious. A steel example crossed the block at an Italian auction in May 2025 for just under $67,000, while another sold at Monaco Legend Group in October 2024 for a shade over $162,000, and dealer asks north of $250,000 exist for exceptional untouched pieces. A salmon dial example carried an estimate approaching $200,000 to $270,000. Condition, dial variant and paperwork explain almost all of that gap. Steel is the story here, with fewer than about 300 built out of roughly 800 total, which is why yellow gold examples trade at a meaningful discount despite the metal value.

Direction of travel is steady rather than dramatic. Vintage complicated Audemars Piguet did not spike the way the steel sports references did in 2021 and 2022, so it has not given much back either. Two forces are working in the reference's favour: the modern steel perpetual calendars now sit well above $95,000, and buyers who work out that a 25654ST is rarer, thinner and often cheaper are steadily crossing over. If you already own one and want a current read on where it sits, we buy these outright and you can start the conversation on our sell an Audemars Piguet watch page.

HEAD TO HEAD

Audemars Piguet Royal Oak 25654ST Comparison

The steel Quantieme Perpetuel against the alternatives buyers actually cross-shop.

Audemars Piguet Royal Oak 25654ST vs. Audemars Piguet Royal Oak 25554ST (The Original)

The 25554 came first and is roughly six times rarer in steel, with something like 49 pieces against the 25654's production run. It is also about three quarters of a millimetre thinner, which you can genuinely feel. What you give up is water resistance, since the thicker 25654 case was specifically revised to seal better, and you give up any realistic chance of finding one. A steel 25554ST sold at Christie's Hong Kong in April 2025 for just over $97,000. If a collectible-first buyer can find a 25554, that is the trophy. For everyone else the 25654ST is the same watch you can actually buy.

Audemars Piguet Royal Oak 25654ST vs. Audemars Piguet Royal Oak 25820ST (The Successor)

The 25820 is what the 25654 became once Audemars Piguet reintroduced the leap year display with Caliber 2120/2802, and for an owner who intends to actually use the calendar that single change matters a great deal. The dial gains an indication, the setting ritual gains a reference point, and the watch becomes materially easier to live with. Pricing tracks accordingly and unpredictably: a 25820ST made almost $148,000 at Monaco Legend Group in April 2025, while another sold at Antiquorum in December 2024 for under $75,000. Purists prefer the cleaner 25654 dial. Users prefer the 25820.

Audemars Piguet Royal Oak 25654ST vs. Patek Philippe 3940 (The Cross-Brand Call)

The 3940 is the other great thin automatic perpetual calendar of the era and the watch most 25654ST shoppers eventually put on the other side of the scale. It is dressier, quieter, available on leather, considerably easier to find, and it costs a fraction of the steel Royal Oak. What it cannot do is be a sports watch. If you want a perpetual calendar you can wear with a jacket, the Patek Philippe Grand Complications route is the rational purchase. If you want the only perpetual calendar that works with a polo shirt and a steel bracelet, there is no substitute for the Royal Oak.

Robertino's Take

"Every client who cross-shops these three ends up asking me the same thing, so here is the honest answer. The 25554 is the collector's trophy and you will wait years. The 3940 is the smarter money and the better dress watch. But the 25654ST is the only one of the three that does something nothing else has ever done, which is put a perpetual calendar on a steel bracelet and make it disappear under a cuff. You are paying for that, not for the complication."

THE BOTTOM LINE

Is the Audemars Piguet Royal Oak 25654ST Worth It?

The final word on the steel Quantieme Perpetuel.

Yes, if you buy the right example and go in with clear eyes about what ownership involves. The Audemars Piguet Royal Oak 25654ST is the most wearable perpetual calendar ever built, and forty years of engineering progress have not produced a rival that puts this complication this flat on a steel bracelet.

It is perfect for the collector who already owns the obvious pieces and wants something with genuine scarcity behind it, roughly 800 examples across all metals and fewer than about 300 in steel, without moving into a watch that cannot be worn. It suits someone who enjoys the ritual of a mechanical calendar and keeps a winder running. It is the wrong watch for a buyer who wants one watch for everything, because the roughly 40 hour reserve, the three pin correctors, the missing leap year indicator and a case seal from the 1980s all ask for attention that a modern perpetual calendar does not. Buy the condition, not the price. On this reference, an untouched case and an honest bracelet are worth more than any discount, and a genuinely sharp example will hold value long after a polished bargain has stopped finding buyers. If you want to handle one before committing, you can book time with an Audemars Piguet specialist and see it in person.

Robertino's Take

"I have handled a lot of Royal Oaks and this is still the one that surprises people when it comes out of the box. They expect a serious complicated watch and they get something lighter and flatter than the modern steel Royal Oak sitting next to it. My advice has not changed in years: do not chase the cheapest 25654ST on the market, because the cheap ones are cheap for reasons you will pay for later. Find a sharp case, an honest bracelet and paperwork, then stop looking."

Buy Audemars Piguet Royal Oak 25654ST