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Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Audemars Piguet’s Calibre 7138 is a self-winding perpetual calendar introduced in 2025 in three 41 mm watches. Its defining idea is to keep the calendar mechanism in one layer and use a second layer to control corrections through the crown. AP says this layout makes setting more intuitive without making the movement thicker; its published specification gives the calibre a thickness of 4.1 mm.
How does Audemars Piguet Calibre 7138 work?
A perpetual calendar tracks the date through the changing lengths of months and accounts for leap years, so it ordinarily needs little manual correction when kept running. Calibre 7138 displays week, day, date, month, leap year and astronomical moon, alongside hours and minutes. AP describes the launch dial as European-style: day at 9 o’clock, date at 12, and month at 3. A progressive-step date disc is intended to make the date easier to read.
AP says the calibre builds on patented innovations introduced in 2018. The end-of-month cam is integrated with the date wheel, and the month cam is combined with the month wheel, keeping the perpetual-calendar functions in one layer. A second layer manages corrections made with the crown. AP’s stated design aim is to improve ergonomics while retaining a slim profile; this is the manufacturer’s description, not an independent usability or comparative test.
Through the caseback, AP describes finishing that includes Côtes de Genève, satin-brushing, circular graining, satin, snailing and chamfering. Lucas Raggi, AP’s Research and Development Director, called the crown correction system a “major innovation” and said the company put ergonomics at the heart of development. That is AP’s account of its design intent.
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Can you set the Royal Oak perpetual calendar with the crown?
Yes. AP says all adjustments are made through the crown, which handles winding, time setting and calendar corrections. The arrangement removes the calendar correctors normally found on the case side and does not require a separate correction tool. AP’s AP Chronicles explanation of handling time describes four crown configurations, selected by crown position and turning direction. For operating steps, use the Royal Oak Calibre 7138 digital user guide, rather than relying on a generic perpetual-calendar procedure.
Observe the non-correction zone
The Royal Oak guide identifies 9 p.m. to 3 a.m. as a non-correction zone for the perpetual calendar. Before adjusting the calendar, move the time outside that interval as directed in the guide. It provides different recovery procedures depending on whether the watch has stopped for less than or more than 72 hours. These instructions are specific to the Royal Oak version covered by that guide; check the documentation for the exact reference before applying them to another 7138 watch.
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Calibre 7138 specifications
The following are specifications published by Audemars Piguet for the Royal Oak model, not independently measured results.
| Specification | AP-published figure |
|---|---|
| Winding | Self-winding |
| Movement thickness | 4.1 mm |
| Movement diameter | 29.6 mm |
| Power reserve | 55 hours |
| Parts | 420 |
| Jewels | 41 |
| Frequency | 4 Hz / 28,800 vph |
| Functions | Perpetual calendar with week, day, date, astronomical moon, month and leap-year indications; hours and minutes |
These figures do not establish real-world accuracy, longevity or comparative performance. AP’s current Royal Oak specification page lists the technical details; no independent performance-test result is established here.
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Which watches use Calibre 7138?
AP introduced three 41 mm watches with Calibre 7138 in 2025. The collection, case material and dial treatments differ; the steel Royal Oak product page also publishes case dimensions, water resistance and a US recommended price.
| Reference | Collection and case | Dial | Additional published details |
|---|---|---|---|
| 26494BC.OO.D350KB.01 | Code 11.59 Selfwinding Perpetual Calendar; white gold | Smoked blue | 41 mm; other comparable details not stated on the cited launch material |
| 26674ST.OO.1320ST.01 | Royal Oak Selfwinding Perpetual Calendar; stainless steel | Blue Grande Tapisserie | 41 mm case, 9.5 mm watch thickness and 50 m water resistance. AP’s US page displayed a non-binding recommended price of $124,200 excluding taxes when accessed in 2026; price and availability can change. |
| 26674SG.OO.1320SG.01 | Royal Oak Selfwinding Perpetual Calendar; 18-carat sand gold | Matching sand-gold dial | AP reports that this reference won the 2025 GPHG Iconic Watch Prize; other comparable details not stated on the cited page. |
| 26674CD.OO.1225CD.01 | Royal Oak Selfwinding Perpetual Calendar; Bleu Nuit, Nuage 50 ceramic | Not stated on the cited product page | AP’s product page documents this later 41 mm reference as using Calibre 7138; other comparable details not stated here. |
The 2025 launch details are on Audemars Piguet’s Calibre 7138 launch page. Product specifications are available from AP for the steel Royal Oak, sand-gold Royal Oak, ceramic Royal Oak and white-gold Code 11.59. The cited pages do not establish current prices or availability for every reference.
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Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
