Rolex Datejust 278240

Buying Advice

About the Rolex Datejust 278240

The Rolex Datejust 278240 is the current-generation 31mm Datejust in full Oystersteel, paired with a smooth domed bezel and powered by the in-house Caliber 2236 movement. At WatchGuys, we carry pre-owned and unworn Rolex Datejust 278240 examples across the full spectrum of factory dial colors and both bracelet options. The 278240 sits at the entry point of the modern Rolex Datejust 31 lineup, offering the cleanest, most understated configuration in the family. It is the natural successor to the previous-generation Rolex Datejust 178240 and shares the same case dimensions as the fluted-bezel Rolex Datejust 278274.

Rolex Datejust 278240 Specifications

The 278240 measures 31mm in diameter with a thickness of just under 11mm and a lug-to-lug of approximately 36.5mm, putting it firmly in the midsize category. The Oyster case is monobloc with a screw-down case back and Twinlock crown, delivering 100 meters of water resistance. The smooth domed bezel is one of two defining choices for the reference (the other being the fluted bezel on the 278274), and it gives the watch a noticeably more modern, sporty character than its fluted sibling. Inside is the Caliber 2236, a Superlative Chronometer movement featuring the patented Syloxi silicon hairspring, Paraflex shock absorbers, a 55-hour power reserve, and accuracy of plus or minus 2 seconds per day after casing. The sapphire crystal carries the signature Cyclops lens over the date at 3 o'clock.

Rolex Datejust 278240 Dial Options

The 278240 has been produced in one of the widest dial selections of any current Datejust 31 reference. Standard options include white, silver, black, and dark grey index and Roman numeral dials, all paired with stick or Roman hour markers depending on the configuration. The mint green dial introduced in recent years has become one of the most heavily traded variants on the secondary market, alongside the Azzurro blue floral motif dial. Diamond hour marker variants and mother of pearl dials are also produced on the 278240, though many of the most jewelry-leaning dials are reserved for the precious-metal references in the family. The two bracelet options are the three-link Oyster (sportier, with the Easylink comfort extension) and the five-link Jubilee (the original Datejust bracelet, paired with a concealed Crownclasp on this reference).

Rolex Datejust 278240 Price

Pre-owned Rolex Datejust 278240 prices typically range from $7,500 to $11,500 depending on dial, bracelet, condition, and completeness with box and papers. Standard index and Roman numeral dials on the Oyster bracelet sit in the lower half of the range. Mint green dials, Azzurro blue floral motif dials, and diamond hour marker configurations trade at the upper end. Jubilee bracelet examples generally carry a small premium over Oyster examples. Unworn examples with full sets command the strongest prices. For broader budget context, browse our midsize Rolex collection or our women's Rolex collection for adjacent options.

Rolex Datejust 278240 vs. Rolex Datejust 278274

The 278240 and the 278274 are the two stainless steel Datejust 31 references in current production, and the only difference between them is the bezel. The 278240 wears a smooth Oystersteel domed bezel, giving it a cleaner, more contemporary profile. The Rolex Datejust 278274 wears a fluted 18k white gold bezel, which delivers the signature Datejust silhouette and adds a touch of precious metal at the top of the case. Both share the same Caliber 2236, the same 31mm Oystersteel case, the same dial options, and the same Oyster and Jubilee bracelet choices. The 278274 typically trades $1,500 to $3,000 above the 278240 on the secondary market because of the white gold content and the historical association of the fluted bezel with the Datejust line. Buyers who prefer a sportier, more understated look choose the 278240. Buyers who want the classic Datejust look reach for the 278274.

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Why Buy a Rolex Datejust 278240 From WatchGuys

When you shop for a pre-owned Rolex Datejust 278240 for sale at WatchGuys, you get more than a watch. Every piece is authenticated by our in-house watchmakers and backed by a comprehensive set of buyer protections.

Common Questions

Rolex Datejust 278240 FAQ

• What size is the Rolex Datejust 278240?

  The Rolex Datejust 278240 has a 31mm Oystersteel case with a thickness of approximately 11mm and a lug-to-lug of about 36.5mm. It is the midsize option in the modern Datejust family, sitting between the 28mm Lady-Datejust and the 36mm Datejust. The 31mm size wears well on wrists from roughly 5.5 inches to 6.75 inches, and works for both men with slimmer wrists and women who prefer a slightly larger watch than the traditional Lady-Datejust.

• What movement powers the Rolex 278240?

  The Rolex Datejust 278240 is powered by the Caliber 2236, a self-winding mechanical movement with a 55-hour power reserve and Rolex's patented Syloxi silicon hairspring. The Syloxi hairspring offers improved resistance to magnetic fields and temperature variations compared to traditional metal hairsprings. The movement is COSC-certified and tested to Rolex's Superlative Chronometer standard of plus or minus 2 seconds per day after casing.

• Rolex 278240 vs. Rolex 278274, what is the difference?

  The only difference between the Rolex 278240 and the Rolex 278274 is the bezel. The 278240 has a smooth Oystersteel domed bezel for a cleaner, more contemporary look. The 278274 has a fluted 18k white gold bezel for the classic Datejust silhouette. Both share the same 31mm case, Caliber 2236 movement, dial options, and bracelet choices. The 278274 typically trades $1,500 to $3,000 higher on the secondary market due to the white gold content and stronger collector demand for the fluted profile.

• Is the Rolex Datejust 278240 a men's or women's watch?

  Rolex no longer strictly categorizes the Datejust 31 by gender. At 31mm, the 278240 falls into the midsize category and works on a wide range of wrists. It is most commonly worn by women who want more wrist presence than a Lady-Datejust 28, but men with slimmer wrists or anyone seeking a more compact dress watch also wear the 31mm comfortably. For a broader look at women's options, browse our women's Rolex collection.

• How much does a Rolex Datejust 278240 cost?

  Pre-owned Rolex Datejust 278240 prices typically range from $7,500 to $11,500 depending on dial, bracelet, condition, and completeness. Standard index and Roman numeral dials on the Oyster bracelet sit at the lower end of the range. Mint green dials, Azzurro blue floral motif dials, and diamond hour marker variants trade toward the upper end. Unworn examples with full box and papers command the strongest prices. Rolex raised retail prices approximately 7% in January 2026, which has narrowed the gap between retail and secondary market pricing.

• Should I choose the Oyster or Jubilee bracelet on the 278240?

  Both bracelets are factory configurations for the 278240, so it comes down to personal preference. The Oyster bracelet has three flat links and a sportier, more utilitarian profile, with the Easylink comfort extension that adds approximately 5mm to the bracelet length. The Jubilee bracelet has five smaller links, sits closer to the wrist, and is generally considered the dressier and more comfortable option, paired with a concealed Crownclasp on this reference. The Jubilee is the historical Datejust bracelet, introduced in 1945 alongside the original Datejust.

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