
Audemars Piguet are kicking off their 150th anniversary celebrations in a big way by releasing a brand new in-house perpetual calendar movement for 2025, the 7138. It combines several of their past innovations with the specs of the calibre 7121 but the ultra-thin profile of the 5133. It’s presented in a trio of watches, two Royal Oak 41mm editions and a Code 11.59. At the same time the calibre 5135 is being retired with a final limited edition skeleton Royal Oak. AP have also released a handful of other Code 11.59 and Royal Oak recolours for the anniversary that we aren’t featuring here because the perpetual calendars are frankly much more interesting.
Audemars Piguet Royal Oak Selfwinding Perpetual Calendar 41mm Calibre 7138


First up are the two Royal Oak Selfwinding Perpetual Calendar 41mm models. Both of them have the same physical dimensions, measuring 41mm in diameter and a very svelte 9.5mm thick. That slimness is possible thanks to the new proportions of the Calibre 7138, which is itself only 4.1mm thick due to the integration of all of the perpetual calendar functions onto a single layer of the movement.
The key difference between the two models is the case materials. The first is produced in stainless steel, the material that the Royal Oak was originally designed to be made in when it was developed by Gerald Genta in the 1970s. The original RO was a driving force behind the popularity of integrated bracelet steel sports watches in the late 20th century (and their resurgence over the last few years).
Second is the sand gold edition of the Royal Oak Selfwinding Perpetual Calendar 41mm. Sand gold is AP’s proprietary gold alloy that they launched around this time last year with the Royal Oak Flying Tourbillon Openworked. Maybe it’s just a timing coincidence but I associate it with being the signature material of Ilaria Resta, the CEO who took over right before sand gold was introduced. It has a paler tone than yellow gold, which helps tone down the ostentation to tasteful levels.


Both of these watches are being added to the standard range, though there are also extra 150-piece special edition versions that feature commemorative 150th Anniversary casebacks. Through the exhibition casebacks you can see the new movement. It has a 55-hour power reserve and operates at 4Hz with automatic winding. The perpetual calendar complication means it will accurately display the date until the year 2100 without adjustment, if kept wound. It has functions for date, month, leap year, weeks, moonphase, days and 24-hour indicator. The steel edition is £94,900 while the sand gold is price on request.
Price and Specs:
Model:
Audemars
Piguet Royal Oak Selfwinding Perpetual Calendar
Ref:
26674ST.OO.1320ST.01
(non-limited, steel), 26674ST.OO.1320ST.02 (limited edition, steel), 26674SG.OO.1320SG.01 (18k sand gold, non-limited), 26674SG.OO.1320SG.02 (18k sand gold, limited edition)
Case:
41mm
diameter x 9.5mm thickness, stainless steel or 18k sand gold
Dial:
Blue
or sand gold-tone with grande tapisserie pattern
Water resistance:
50m
(5 bar)
Movement:
Audemars
Piguet calibre 7138, automatic, 41 jewels
Frequency:
28,800
vph (4 Hz)
Power reserve:
55h
Functions:
Hours,
minutes, perpetual calendar
Strap:
Stainless
steel or 18k sand gold bracelet
Price:
£94,900
(steel), price on request (18k sand gold)
Audemars Piguet Code 11.59 Selfwinding Perpetual Calendar 41mm Calibre 7138


In addition to the two Royal Oaks above, Audemars Piguet have also released a Code 11.59 Selfwinding Perpetual Calendar 41mm housing the new calibre 7138. It has the same case diameter of 41mm but is slightly thicker at 10.6mm due to the higher sides of the Code 11.59 compared to the Oak. The case here is made of white gold, which feels like the halfway house between the steel and sand gold of the ROs – luxurious while not being overt about it.
The dial is a lovely sky blue colour, matching the steel Royal Oak model. It reminds me somewhat of IWC’s Portugieser collection from 2024 as well as Patek Philippe’s denim style Nautilus. Light blue has always been a popular colour in horology so I’m loathe to call it a trend exactly, but it’s certainly a colour that’s on people’s radar in a big way at the moment. The dial also features the Code 11.59’s signature embossed texture with its basket weave-esque design.
Housed below the dial is, as mentioned, the new calibre 7138. It has the same specs as the Royal Oaks, with a 55-hour power reserve and all that goodness. The Code 11.59 Selfwinding Perpetual Calendar 41mm is also available in either a standard edition or a 150-piece limited run with commemorative 150th anniversary caseback. It’s priced at £94,900.
Price and Specs:
Model:
Audemars
Piguet Code 11.59 Selfwinding Perpetual Calendar
Ref:
26494BC.OO.D350KB.01
(non-limited), 26494BC.OO.D350KB.02 (limited edition)
Case:
41mm
diameter x 10.6mm thickness, 18k white gold
Dial:
Smoked
blue with embossed signature dial, blue subdials, 18k white gold hands and hour markers
Water resistance:
30m
(3 bar)
Movement:
Audemars
Piguet calibre 7138, automatic, 41 jewels
Frequency:
28,800
vph (4 Hz)
Power reserve:
55h
Functions:
Hours,
minutes, perpetual calendar
Strap:
Blue
textured rubber with calfskin lining, 18k white gold folding clasp
Price:
£94,900
Audemars Piguet Royal Oak Perpetual Calendar “150th Anniversary” Openworked 41mm
In addition to a new movement, Audemars Piguet are retiring one as well. The Royal Oak Perpetual Calendar “150th Anniversary” Openworked 41mm limited edition marks the swansong of the calibre 5135. It’s the movement that has powered AP’s openworked perpetual calendars for the past decade, based on a movement that traces its heritage to 1978. It’s been used in several notable references including 2023’s Cactus Jack edition.
Here, it’s housed in a 41mm case in titanium, following the classic design shapes of the Royal Oak with its integrated bracelet and octagonal bulk metallic glass bezel (learn more about BMG here. The dial is inspired by the Ref. 25729 pocket watch held in the Musée Atelier Audemars Piguet (AP’s museum). It has a rich blue colour on the inner bezel and skeletonised subdials. It matches the vibrant tone of the moonphase display at 6 o’clock.
The Royal Oak Perpetual Calendar “150th Anniversary” features an exhibition caseback featuring an engraving that denotes it as a limited edition out of 150 pieces. The skeletonised rotor also allows a very good view into the inner workings of the movement, a fitting way to bid goodbye to the calibre. It’s also price on request.
Price and Specs:
Model:
Audemars
Piguet Royal Oak Perpetual Calendar Openworked ‘150th Anniversary’ Limited Edition
Ref:
26585XT.OO.1220XT.01
Case:
41mm
diameter x 9.9mm thickness, titanium
Dial:
Openworked
with blue brass inner bezel
Water resistance:
20m
(2 bar)
Movement:
Audemars
Piguet calibre 5135, automatic, 38 jewels
Frequency:
19,800
vph (2.75 Hz)
Power reserve:
40h
Functions:
Hours,
minutes, perpetual calendar
Strap:
Titanium
bracelet with folding clasp
Price:
Price
on request, limited to 150 pieces
More details at Audemars Piguet.
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