Audemars Piguet Royal Oak Perpetual Calendar
Extra-Flat Automatic

With a movement of only 2.89 mm and a case 6.3 mm thick, the Royal Oak Perpetual Calendar Extra-Flat Automatic (Ref. 26586IP.OO.1240IP.01) is the world's thinnest self-winding perpetual calendar watch and represents the latest technological breakthrough by Audemars Piguet. For the conception of this new timepiece, the Manufacture's R&D team integrated development, design and ergonomics of the movement to enhance its efficiency, robustness and reliability. The result is an extra-flat perpetual calendar automatic watch equipped with a complex movement, redesigned to be integrated in an elegant ultra-thin case. To achieve an extra-flat movement just 2.89 mm high, the perpetual calendar functions, usually divided into three levels, were combined into a single level. This led to the development of two pioneering patented innovations: the month-end cam was integrated into the date wheel, and the month cam into the month wheel. The structure of each component was also optimised, thus reducing adjustment and assembly time. Even the dial has been redesigned compared to previous Royal Oak perpetual calendar watches (such as Ref. 26574). The day, date and month counters have been enlarged to ensure optimal readability, while the day/night indicator, positioned at 8 o'clock, has been added symmetrically to the leap year indicator, placed at 4 o'clock. An evolution of the RD#2 prototype in 950 platinum presented at SIHH 2018, the Royal Oak Perpetual Calendar Extra-Flat Automatic combines two metals, titanium and 950 platinum, for a very elegant result and extraordinary lightness on the wrist. The movement, case, bracelet and dial are finished by the expert hands of the Maison's master craftsmen: the alternation of polished and satin-finished surfaces on the case, bracelet and bezel enhances the aesthetic contrast between the two materials. Moreover, the dial of this latest model does not feature the blue "Grande Tapisserie" motif, replaced by a satin finish in the same colour that enhances legibility and aesthetics. Although the advent of simultaneous multi-parameter technologies has enabled Audemars Piguet to revolutionise the conception of its perpetual calendar movement, the Maison's latest launch is essentially the result of the efforts of engineers, designers, programmers and watchmakers who have outdone themselves in creating a new generation of calibres and watches designed specifically for a contemporary lifestyle. The balance between traditional watchmaking and emerging technologies has always been at the heart of Audemars Piguet's savoir-faire. The emergence of CAD (Computer Aided Design) and CNC (Computer Numerical Control), for example, stimulated the brand's creativity in the 1980s, charting a new course for the company and the entire industry Today, the Royal Oak Perpetual Calendar Extra-Flat Automatic is the world's thinnest perpetual calendar watch and represents a major turning point for the House of Le Brassus, as it lays the foundations for a new generation of complicated watches capable of reconciling aesthetic refinement, high ergonomics, technical complexity, ancestral savoir-faire and contemporary lifestyle.

Technical Specifications

Royal Oak Perpetual Calendar Extra-Flat Automatic


Perpetual calendar with day, date, astronomical moon, month, leap year, day/night indication, hours and minutes.


Titanium case (41 mm diameter), satin-brushed; sapphire crystal and back with anti-reflective coating; bezel and intermediate links in polished 950 platinum; screw-down, personalised titanium crown. Water-resistant to 20 metres.


Brushed blue dial, blue counters, applied hour markers and Royal Oak hands in white gold with luminescent coating.


Satin-finished titanium bracelet with polished 950 platinum intermediate links and titanium AP folding clasp.


  • Manufacture calibre 5133, self-winding.
  • Total diameter: 32 mm (14¼ lines).
  • Total thickness: 2.89 mm.
  • Number of components: 256.
  • Number of rubies: 37.
  • 40-hour power reserve.
  • Balance frequency: 2.75 Hz (19,800 vibrations per hour).