Collectability In-Depth: Patek Philippe Perpetual Calendar Ref. 725

Patek Philippe didn’t invent the perpetual calendar, but it might have made it famous.

The earliest known perpetual calendar pocket watch made by Thomas Mudge in 1762. The calendar has a window with a rotating disc that scrolls the name of each month with its number of days. A still smaller disc under February rotates once every four years, accounting for leap years. Image credit: Patek Philippe Museum

The earliest known Patek Philippe perpetual calendar pocket watches date to the 1860s, nearly a century after English watchmaker Thomas Mudge made the first perpetual pocket watches in 1762 (one of which now sits in the Patek Philippe Museum). Over the following decades, it made perpetual calendars (or “QP” for the French quantieme perpetuel), usually as unique or special commissions for big-spending clients.

The first perpetual calendar wristwatch made by Patek Philippe in 1925. Its movement, recorded in the company’s Archives, and partially manufactured in 1899, was never used before its completion in 1925 for this wristwatch. Image credit: Patek Philippe Museum

By 1925, Patek Philippe shrunk its mechanism into the world’s first perpetual calendar wristwatch. After that came the first retrograde QP and, eventually, serialized production. While Patek Philippe’s perpetual calendar wristwatches have become some of the most collectible vintage watches, the pocket watches don’t always get the same attention.

Made between 1940-1943, this is the earliest Patek Philippe ref. 725 in the Patek Philippe Museum. It was delivered to Tiffany & Co., New York in 1945. Image credit: Patek Philippe Museum

But these pocket watches were essentially developed alongside the wristwatches, exhibiting the same watchmaking and craft. The first serialized perpetual calendar pocket watch ref. 725 came in 1940, a year before its wristwatch counterpart ref. 1526. As I discovered, it’s also a bit misunderstood.

What is the Patek Philippe Perpetual Calendar Ref. 725?

Magnificent movement: manual caliber 17-170 perpetual calendar with moon phases of a Patek Philippe ref. 725/2J made in 1951. Image credit: Collectability

Patek Philippe produced the ref. 725 in extremely low numbers from 1940 until the early 1980s—it’s estimated that fewer than 100 were made. In researching this article, I documented 38 examples across 41 auction sales dating back to 1989. Extracts put production as late as 1983 and sales as late as 1986.

Case. The ref. 725 features a 46mm, three-piece precious metal case produced by Wenger (key number 1), which also made the case for most ref. 2499 perpetual calendar chronograph wristwatches, among other Patek Philippe watches. It’s an open-face pocket watch with polished bezel and brushed mid-case.

Movement. It uses the caliber 17-170, a large 17-ligne movement with Victorin Piguet perpetual calendar module on the dial side. This is an instantaneous perpetual calendar mechanism with three setting pins in the case.

Dial. The silver dial of the ref. 725 is traditional Patek Philippe, made by Stern Frères with a hand-engraved hard enamel signature. There are two main dial series:

First Series: Four sub dial layout (c. 1941-1951)
Second Series: Straight-line “American” calendar (c. 1951-1983)

Reference variants. Ref. 725 has four variants: refs. 725, 725-2, 725-3, and 725-4. These references seem to be roughly chronological when arranged by movement number, with ref. 725 and ref. 725-2 coming before ref. 725-4. The only known ref. 725-3 sits between the change from ref. 725-2 to 725-4. There seems to be some confusion about how to categorize the ref. 725. I observe that First Series and Second Series dials do not fit neatly into reference variants. Mostly, First Series dials are found in ref. 725-2 and Second Series dials in ref. 725-4 However, there is some overlap, with the Second Series found in some late “transitional” ref. 725-2s.

Patek. Philippe ref. 725 timeline of series production

Case metals. Here’s the breakdown of case metals among surveyed examples (known):

32 yellow gold
3 pink gold
3 platinum

Patek Philippe ref. 725P belonging to Henry Graves Jr. Made between 1945 -1946 and delivered in 1947. Image credit: Patek Philippe Museum

One of the these platinum examples was delivered to Henry Graves Jr. in 1947 and now sits in the Patek Philippe Museum. Including Graves’ watch, at least five ref. 725s are on view in the Museum.

‘First Series’ Perpetual Calendar Ref. 725

Patek Philippe ref. 725 First Series dials. Image credit: Tony Traina

The First Series of the ref. 725 is defined by four calendar sub dials: Date at 3 o’clock, moon phase and seconds hand at 6 o’clock, day at 9 o’clock, and month at 12. The leap year is typically also indicated within the 12 sub dial.

Patek Philippe ref. 725 perpetual calendar first series without leap year indication. Sold at Phillips, Hong Kong in 2018 for KK$350,000. Image credit: Phillips

Collector’s tip: Interestingly, there are rare dial variants on the ref. 725 which have no leap year indicator at 12 o’clock. The above example was the final example before Patek Philippe transitioned to the straight-line American calendar. It last sold in 2018 for HK $350,000.

Another rare dial variant on a ref. 725: this watch sold through Collectability in 2020 and features a dial that does not depict the leap years. Image credit: Collectability

In addition to the sub dial layout, most First Series ref. 725 examples have a few common characteristics: A round “pendant” bow with exposed crown, leaf hands, applied Arabic numerals, and short “Patek Philippe” signature (though the first few were produced in the early ‘40s and feature a long signature). There’s also a noticeable hallmark on the crown’s housing at 12 o’clock.

Bows in a row: three of the bow variants found on a Patek Philippe ref. 725. Image credit: Tony Traina

Variation. The earliest examples have variation in the bow, with a couple having a rectangular shape. Finally, the last few First Series examples transition to more modern dauphine hands.

The coveted Tiffany & Co. signature on a Patek Philippe ref. 725/2 made in 1952. Image credit: Collectability

Retailer signatures. In the First Series, I observed two examples signed by New York retailer Tiffany & Co. and one signed Gübelin for the Swiss retailer.

Case Metals

While most ref. 725s feature yellow gold Wenger cases, a few rare examples have come to market in pink gold or platinum. All of the case metal variation is seen in the First Series.

A rare Patek Philippe ref. 725 in platinum, sold inn May 2013 for CHF 303, 750. Image credit: Christies

Platinum. There are three known platinum examples. In addition to Graves’, Christie’s sold one in 2013 for $317,200, the highest-ever public result for a ref. 725.

Patek Philippe ref. 725 in rose gold sold at Christie’s Geneva in May, 2025 for CHF 50,400. Made in 1951. Image credit: Christies

Pink gold. There are three known examples of the ref. 725 in pink gold. They have consecutive movement numbers, which means they might’ve been produced as a batch:

931089: yellow
931090: pink
931091: pink
931092: pink
931093: unknown
931094: yellow

It leaves open the possibility of perhaps one more pink gold ref. 725 in this batch (are there other, unknown pink gold batches?).

The Only Known Ref. 725-3

A Patek Philippe ref. 725/3 sold at Phillips for $226,800 in 2022. Made in 1954. Image credit: Phillips

In 2022, Phillips sold the only known example of a ref. 725-3 ($226,800). Its sub dials are flipped, with the date at 12 and the month at 3 o’clock, making it so far unique to the market. Interestingly, its movement and case numbers sit between the transition from refs. 725-2 to 725-4, offering some evidence that it may have been some sort of short-lived transitional or test reference.

Second Series Ref. 725: The “American” Straight Line Calendar

Straight to the point: Patek Philippe ref. 725/4 with the ‘American’ straight-line calendar indicator. Made in 1972. Image credit: Patek Philippe Museum

Around the early 1950s, we see Patek Philippe switch the dial layout of the ref. 725 from four sub dials to a straight-line “American” calendar with month, date, and day discs displayed in a single aperture below 12 o’clock. (American refers to a single aperture showing month, date, and day.) While the sub dial layout is seen in references such as the perpetual calendar chronograph ref. 1518 and ref. 2499, the in-line layout is used in the modern ref. 5236.

The transition to the American layout actually comes before the move from the ref. 725-2 to 725-4, with the final few examples of the ref. 725-2 featuring the updated straight-line layout.

All observed examples of the Second Series ref. 725 also feature a yellow gold case, dauphine hands, baton indices, the short “Patek Philippe” signature, and a moonphase at 6 o’clock. Together, it’s a more modern, updated aesthetic than the First Series ref. 725.

Rounded window: An unusual calendar aperture seen on this Patek Philippe ref. 725 sold at auction in November, 2015 for CHF 88,750. Made in 1951. Image credit: Antiquorum

Collector’s tip: I found one example with a rounded aperture (sold CHF 88,750 in 2015) instead of the typical squared-off window. Chronologically, it’s also the first observed straight-line calendar—with the earliest movement number—so perhaps it was a test.

What’s the Difference Between Refs. 725-2 vs. 725-4?

Ref. 725 dials fit neatly into First Series (four sub dials) and Second Series (American calendar). However, these dials don’t exactly fit into the case reference variants.

Patek Philippe ref. 725/4. Image credit: Sotheby’s

So what is the difference between refs. 725-2 and 725-4, the two most common case variants? Look at the crowns:

Ref. 725-2 has a crown that’s completely exposed underneath the bow.
Ref. 725-4 features small crown guards.
Patek Philippe ref. 725 winding crown variations. Image credit: Tony Traina

There are a few late ref. 725-2 cases with the straight-line calendar (all dating to 1951). Soon after, Patek Philippe switched to the ref. 725-4 case, all of which feature the straight-line calendar. As is often the case, it’s possible Patek Philippe had a few leftover ref. 725-2 cases after switching the dial and movement layout, thus the overlap.

In total, I documented:

Ref. 725: 6 examples (1940-1951)
Ref. 725-2: 19 examples (1947-1952)
Ref. 725-3: 1 example (1954)
Ref. 725-4: 12 examples (1956-1983)

NB: A few of the ref. 725 examples may actually be -2 or -4 references that were not completed cataloged at the time of sale.

Market Pulse

Market results for the ref. 725 have been remarkably steady over the past 35 years. In October 1990, a pink and yellow gold example both sold for about $40,000. Of course, this was before anyone might’ve guessed that the pink was one of just a few known.

Patek Philippe ref. 725 sold at Christie’s Geneva in May, 2025 for CHF 50,400. Made in 1951. Image credit: Christies

While information has grown, interest in pocket watches has not. Recently, a fresh-to-market pink ref. 725 sold for $60,000–twice. It first appeared at a small French sale in December 2024. Perhaps the winner thought they might make a quick buck, because the same watch appeared on a bigger stage at Christie’s Geneva six months later. But it sold for almost the exact same price, still a relative bargain all things considered. In the rarified air of Patek Philippe perpetual calendars, nothing sneaks under the radar and buying opportunities still exist especially with complicated pocket watches.

Since 2020, we’ve seen an average of two ref. 725s appear at auction per year. Usually, they’re watches already known to the market. We are seeing increased interest and prices trending upward with Patek Philippe pocket watches, especially complicated pocket watches. As with all vintage Patek Philippe watches, condition is important. Dials with hard enamel intact, sharp apertures, and crisp cases command a premium.

While there are “rules” to the ref. 725: most ref. 725-2s feature a First Series dial, and most ref. 725-4s feature a Second Series dial, there are exceptions, especially at the beginning and end of production runs. This is what makes collecting fun—it’s also where you can find rarity.

How to Collect the Patek Philippe Perpetual Calendar ref. 725

Beauty in the dial: a Patek Philippe ref. 725J. Image credit: Collectability

Patek Philippe’s perpetual calendar family has long represented the pinnacle of watch collecting. From the ref. 1518 to ref. 3448, it’s the essence of the manufacturer. But there’s no way around it: these are expensive watches, even if you’re lucky enough to find one in collectible condition.

Meanwhile, across 40 years, the ref. 725 holds the DNA of nearly every other Patek Philippe perpetual calendar, wristwatch or pocketwatch. The early four-sub dial layout laid the groundwork for the perpetual calendar chronographs that followed; the later straight-line layout feels bold, modern, and just as relevant today.

While I prefer the clean, modern aesthetic of the American calendar, there’s no denying the historical appeal of a First Series ref. 725.

And look: I commend anyone who can wear around a ref. 2497 or ref. 2499 on their wrist. But for the rest of us, having a large Patek Philippe perpetual calendar pocket watch propped up on our desk doesn’t sound so bad, does it?

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Thanks for reading our in-depth article on the ref. 725. We’ll be back soon with an examination of the ref. 844 Perpetual Calendar Minute Repeater. Any conclusions here are based on research and a survey of publicly sold examples, future discoveries may change them!

Tony Traina is the editor and founder of Unpolished, the newsletter for watch collectors. He’s a former editor at Hodinkee and also contributes to GQ, Sotheby’s, and Revolution. He’s a collector who started in watches while a practicing attorney.

September 2025