A fake Audemars Piguet Royal Oak Perpetual Calendar copies the 41mm ref. 26574, and the fastest way to judge one is the movement: the genuine watch runs AP calibre 5134, a 4.31mm automatic with 374 parts, 40 hours of power reserve, and a real perpetual calendar. Most replicas use a decorated Asian automatic or a modular movement, so the sub-dials look right while the calendar logic does not work. If a seller cannot explain the movement or show the caseback, treat the watch as a low tier build.
What makes the genuine Royal Oak Perpetual Calendar different?
The genuine ref. 26574 uses a 41mm octagonal case, a Grande Tapisserie dial, and four sub-dials: day and date at 3, month and leap year at 12, moonphase at 6, and week of year at 9. It measures about 9.5mm thick on a steel bracelet, which is unusually slim for a perpetual calendar. The 5134 movement keeps the calendar correct until 2100, and the week indicator tracks the 52-week cycle automatically.
How to spot a fake Audemars Piguet Royal Oak Perpetual Calendar
Start with case thickness, then work outward. Replica cases often measure 11mm to 13mm because the movement module sits on top of a base automatic. On the wrist that extra 2mm to 3mm changes the flat Royal Oak profile, and the bracelet end links may not sit flush.
1. Case thickness and profile
The genuine 26574 is about 9.5mm thick. Ask for a caliper photo next to a ruler or a known reference object, not a wrist shot. A replica that measures 12mm is a different watch on the wrist.
2. Movement and caseback
Open the caseback or ask for macro photos. Genuine calibre 5134 shows Geneva stripes, polished bevels, a gold rotor with the AP family crest, and engraved reference details. Replica rotors are usually stamped metal with shallow engraving and a generic automatic underneath.
3. Sub-dial layout and function
Test every function: set the date, advance the month, and watch the leap year indicator move on March 1. On most replicas the week-of-year hand at 9 is fixed or moves with the date. Moonphase discs on fakes often use a printed sticker rather than a rotating disc with a proper 29.5-day cycle.
4. Dial and hand finishing
Genuine Grande Tapisserie squares are cut with sharp, deep edges and even spacing. Replica dials use a softer stamped pattern, and the square edges blur under a loupe. Sub-dial rings, printed text, and the AP logo are the next tells, because fake printing is often thicker and less crisp.
5. Bracelet, weight, and feel
The genuine steel bracelet has tight tolerances, polished bevels on every link, and no rattle. A replica often feels lighter, has sharp edges on the links, and uses a clasp with a stamped logo instead of a raised or engraved one.
Do replica perpetual calendars actually work?
Most do not. A true perpetual calendar needs a complex program wheel and a mechanism that accounts for 28, 29, 30, and 31-day months plus leap years. Replicas typically use an annual calendar module or a simple triple-date layout that needs manual correction at the end of February, and only a small number of high-end builds approximate the full function.
What should you check before buying?
- Ask for a caliper measurement of case thickness.
- Request macro photos of each sub-dial and the caseback.
- Ask whether the leap year and week-of-year indicators move.
- Confirm the movement base and service options.
- Check water resistance claims and crown action.
A seller who answers these questions with photos and specifics is more reliable than one who only shows marketing renders. If the price is under $300 for this complication, the calendar is almost certainly cosmetic.
Price tiers and what they mean
Entry replicas of this reference sell for $250 to $500 and use stamped dials with non-working calendar displays. Mid-tier builds at $600 to $1,200 add a better case finish and a decorated automatic, but the calendar remains simple. Top-tier builds above $1,200 may include a working moonphase and corrected sub-dial spacing, though the movement still is not a 5134.
FAQ
Does a fake AP Royal Oak Perpetual Calendar have a working perpetual calendar?
Rarely. Most replicas show day, date, month, and moonphase but need manual adjustment after February, so they work like an annual calendar or a triple-date watch.
What is the biggest giveaway on this replica?
Case thickness. A genuine 26574 is 9.5mm, and most fakes are 11mm or more because the movement module cannot fit the slim case.
Are replica AP perpetual calendars reliable?
Reliability varies by movement. A Miyota-based build is more dependable than a cheap 7750 module, but servicing is difficult and parts are not standardized.