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    Patek Philippe Perpetual Calendar lug width

    Watch line15 references

    Lug widths across the line

    Patek Philippe Perpetual Calendar references use 18 mm or 20 mm or 21 mm depending on the reference and case size, so check yours in the list below. The most common is 20 mm (9 of 15 references with a known width).

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    15 Patek Philippe Perpetual Calendar references

    FAQ

    What lug width does the Patek Philippe Perpetual Calendar use?

    Patek Philippe Perpetual Calendar references use 18 mm or 20 mm or 21 mm depending on the reference and case size, so check yours in the list below. The most common is 20 mm (9 of 15 references with a known width).

    Do all Patek Philippe Perpetual Calendar references take the same strap?

    No. 5 different lug widths appear across the line, often by case size or generation. Check the reference engraved on the case back or between the lugs.

    What lug width does the Patek Philippe 5140 use?

    Patek's 2006 technical data for the white gold 5140G gives 19 mm between the lugs, on a 37.20 mm case. Check the exact metal and reference before ordering, since the Smartlet index lists each 5140 variant separately.

    What strap and clasp does a modern Patek perpetual calendar come with?

    Patek fits hand-stitched alligator straps with a gold or platinum fold-over clasp: chocolate brown with a white gold clasp on the 5320G-011, navy blue with a white gold clasp on the 5327G-001, and navy blue with a platinum clasp on the 5236P-001, now discontinued.

    How have case sizes changed from the 3940 to today?

    The 3940 measured 36 mm, the 5140 grew to 37.2 mm in 2006, the 5327 to 39 mm in 2016, the 5320G is 40 mm and the 5236P is 41.3 mm. Strap width usually changes with each new case, so match the reference rather than the line.

    Can I swap the sapphire case back for a solid one?

    Patek supplies its perpetual calendars with two interchangeable backs, a sapphire back and a solid gold one. For the 5140 Patek says the solid back should be fitted only by an Authorized Patek Philippe Service Center.

    How do I reset the calendar if the watch stops?

    The calendar indications are set through push pieces recessed in the side of the case, using the supplied correction stylus. On the 5140 there are four, for day, date, month and moon phase; on the 5236P three correctors sit between 9 and 2 o'clock with the moon corrector at 8.

    The story of the Patek Philippe Perpetual Calendar

    In 1925 Patek Philippe cased a movement built in 1898 for a lady's pendant watch, gave it engraved lugs and a strap, and made the first perpetual calendar wristwatch. A century later the same complication, which needs no correction until 2100, still sits at the heart of the Patek catalogue.

    1,461 daysMechanical memory of the calibre 240 Q perpetual calendar, one full leap-year cycle
    122 years and 45 daysTime before the 5140's moon phase drifts by one day
    118Extra parts needed for the single-line display of the 5236P

    Chapters

    1. 2006 to today
      Bigger cases, new displays

      The 37.2 mm Ref. 5140 replaced the 3940 in 2006, and the 39 mm Ref. 5327 with Breguet numerals took over in 2016. In 2021 the Ref. 5236P showed day, date and month on a single line, a first for a Patek wristwatch.

    2. 1985 to 2006
      The quartz crisis answer

      With the Swiss industry battered by quartz, Patek launched the ultra-thin Ref. 3940 in 1985 on the micro-rotor calibre 240 Q. It replaced the rectangular day and month apertures with sub-dials at 3 and 9 o'clock and became, in Patek's words, the first highly complicated watch in regular production. The Ref. 5140 replaced it in 2006.

    3. 1962 to 1985
      The first self-winding perpetual

      In 1962 the Ref. 3448 made the perpetual calendar self-winding, a first for any watchmaker, in a 37.5 mm case Italian collectors nicknamed Padellone. Its successor, the Ref. 3450 of 1981, added a small window showing the leap-year cycle.

    4. 1941 to 1963
      Serial production and a signature face

      With the Ref. 1526, Patek became the first maker to produce a perpetual calendar wristwatch in series. Its layout, day and month in two windows under 12 and a date and moon sub-dial at 6, became the house signature. The larger Refs. 2497 and 2438/1 added a centre seconds hand from 1951.

    5. 1930 to 1944
      Unique pieces and experiments

      A cushion-shaped perpetual followed in 1930, and in 1937 the Ref. 96 became the first wristwatch with a retrograde perpetual calendar. In 1944 Patek made two Ref. 1591, the first perpetual calendar with a sweep seconds hand, in a waterproof case with luminous dial and hands.

    6. 1898 to 1927
      A pendant movement reaches the wrist

      Patek built a perpetual calendar movement in 1898 for a ladies' pendant watch that never sold. In 1925 it was recased as a 34.4 mm yellow gold wristwatch with hand-engraved lugs, No. 97 975, the first perpetual calendar wristwatch by any maker. It was sold in 1927 to the American collector Thomas Emery.

    Worn by

    Andy WarholCulture1978

    The artist owned a 1977 yellow gold Ref. 3448, sold to its first owner in February 1978 and kept until his death. It was the most expensive wristwatch in Sotheby's 1988 sale of his jewellery and watches.

    Ringo StarrMusic

    The Beatles drummer owned a yellow gold Ref. 3448 that came to auction in 2015 on a worn Asprey strap; its lugs showed it had been well worn.

    Philippe SternBusiness

    Patek's president and owner, who launched the Ref. 3940 in 1985, wore one as his daily watch.

    Charles SternBusiness

    Patek's president had the non-chronograph Ref. 1527 perpetual calendar, one of only two 1527 made around 1943, made for and worn by himself. It is now in the Patek Philippe Museum.

    Jean-Claude BiverBusiness

    The watch executive owns one of the two Ref. 3448 cased in platinum by Jean-Pierre Hagmann long after the model was discontinued.

    Cruz BeckhamMusic2026

    Wore a rose gold Ref. 5327R-001 with ivory lacquered dial at a London Fashion Week event, after wearing the same watch at his father's Hollywood Walk of Fame ceremony earlier that year.

    Moments

    Andy Warhol's 1977 yellow gold Ref. 3448 passed through Sotheby's New York in 1988 and Sotheby's Geneva in 2014, then sold at Christie's New York on 5 December 2023 for USD 378,000.

    Sold at Julien's Auctions in a sale of property of Ringo Starr and Barbara Bach, the yellow gold 3448 made $179,200, against an estimate of $80,000 to $100,000.

    One of only two Ref. 1591, a steel perpetual with luminous dial reputedly made for an Indian maharaja who played polo, sold at Christie's in 2007 for SFr. 2,513,000. Its dial and hands later inspired the 5320G.

    In 1975 former Patek director Alan Banbery received a unique 3448 whose moon phase was replaced by a four-quadrant leap-year display, later used on the 3940. It sold at Christie's in 2008 for SFr. 1,840,900.

    Italian collectors named the 3448 Padellone, the frying pan, for its large, thin 37.5 mm case and raked bezel.

    Generations and strap changes

    1. 2021
      Ref. 5236P In-line

      A new display showing day, date and month on one line under 12, inspired by a 1972 pocket watch in the Patek museum. The calibre 31-260 PS QL uses four coplanar discs, two of them for the date, and three patent applications were filed. The reference is now listed as discontinued.

      41.3 mm platinum case, 11.07 mm thick, on a navy blue alligator strap with platinum fold-over clasp.

    2. 2017
      Ref. 5320G

      A vintage-styled perpetual with the dial layout of the Refs. 1518 and 1526, luminous hands, a box sapphire crystal and calibre 324 S Q. Its stamped case with three-tier lugs was inspired by the Ref. 2405.

      40 mm white gold case with three-tier lugs, on a chocolate brown alligator strap with white gold fold-over clasp.

    3. 2016
      Ref. 5327

      Replaced the 5140 with a Calatrava-style case with scalloped flanks, applied Breguet numerals and the same calibre 240 Q.

      Case grows to 39 mm (9.71 mm thick) with wider lugs than the 5140 and 3940.

    4. 2006
      Ref. 5140

      A slightly enlarged 3940 with a convex bezel and a bigger date sub-dial, still on calibre 240 Q. It launched in white gold and was announced as the eventual replacement of the 3940.

      Patek's technical data: 37.20 mm diameter, 8.90 mm thick, 19 mm between the lugs (white gold 5140G), on an alligator strap with gold fold-over clasp.

    5. 1985
      Ref. 3940

      Launched with the 3970 perpetual chronograph during the quartz crisis, it used the ultra-thin micro-rotor calibre 240 Q and was the first Patek perpetual with leap-year and 24-hour sub-dials. It was made until 2006 and was Philippe Stern's own daily watch.

      36 mm case, replacing the 37.5 mm Ref. 3450.

    6. 1981
      Ref. 3450

      Successor to the 3448 and the first regular production Patek perpetual to show where the year sits in the leap-year cycle, through a small round window between 3 and 4 o'clock that turns red in a leap year. Revolution counts 244 examples made until 1985.

    7. 1941
      Ref. 1526

      The first serially produced perpetual calendar wristwatch, hand-wound with calibre 12-120 Q. Revolution counts 210 examples, mostly yellow gold, a few rose gold and one known in steel.

      34 mm case.

    8. 1925
      No. 97 975

      The first perpetual calendar wristwatch, built around an 1898 pendant movement, with small seconds at 9 and moon phase at 3, most likely because the dial was turned from the movement's original orientation. It is now in the Patek Philippe Museum in Geneva.

      34.4 mm yellow gold case with hand-engraved lugs securing it on a strap.

    About Patek Philippe

    Founded in 1839 in Geneva, Switzerland.

    The Patek Philippe story

    Help

    What is lug width?

    The gap between the two lugs that hold the strap, in millimetres. A new strap must match it exactly: 20 mm lugs take a 20 mm strap.

    Measure it in 30 seconds

    1. Take the strap off, or look at the back of it: many straps print their width.
    2. Measure the inside gap between the lugs with a caliper or a millimetre ruler.
    3. Round to the nearest whole millimetre. Most watches use 18, 20 or 22 mm.

    Strap, quick release or system?

    Most watches use spring bars, so any strap of the right width fits. Many smartwatches use their own band system instead, such as Apple Watch bands or Garmin QuickFit.