Oris · Oris Calibre 400

Oris Aquis Date, Divers Sixty-Five and ProPilot X power reserve: inside the Calibre 400

The Oris Aquis Date Calibre 400, Divers Sixty-Five Calibre 400 and ProPilot X Calibre 400 all run on Oris's own Calibre 400, which lasts about 120 hours off the wrist. That's five full days, long enough to skip a whole working week.

Updated September 2026 · Based on manufacturer specs, published reviews and watchmaker/owner reports

Watches that use the Calibre 400

Oris sells two kinds of watch that can look almost identical: ones with a Sellita-based movement and ones with its own Calibre 400. The name usually tells you, because Oris puts "Calibre 400" in the model name. The reference number is the other giveaway. The second group of digits is the calibre, so an 01 400 reference has the Calibre 400, while an 01 733 reference has Oris's Sellita SW200-based 733.

Several of these references are grouped by family: dial colour and strap change the last digits. Check the full number on the caseback or warranty card if you need to be sure.

Specs at a glance

History and where it came from

For most of its history Oris used bought-in movements, first ETA and then Sellita, with an Oris rotor and its own calibre number. Its in-house work started with the hand-wound Calibre 110 in 2014, which has a 10-day reserve, but that and its descendants were expensive, complicated watches. The Calibre 400, announced in October 2020, was the first Oris-designed movement meant for everyday watches.

Oris says it started the project about five years earlier, under COO Beat Fischli. The brief was straightforward: longer reserve, better resistance to magnetism and enough durability to justify a 10-year warranty. As Monochrome notes, it's a "manufacture" movement in the sense that Oris designed it, but parts are made by a network of Swiss suppliers rather than all under one roof.

The first watch to get it was the 43.5 mm Aquis Date Calibre 400 in November 2020. The 41.5 mm Aquis followed in 2021, then the ProPilot X and the Divers Sixty-Five in 2022. The 401 (small seconds) arrived within three months of the launch, in the Carl Brashear limited edition, and the 403 (pointer date for the Big Crown) followed later in 2021, and Oris now uses the family across most of its mid-priced range. Its cheaper models still use the Sellita-based 733.

Accuracy in the real world

Oris quotes -3/+5 seconds a day, slightly tighter than the COSC chronometer range of -4/+6. The movement isn't sent to COSC, so the figure is Oris's own regulation spec rather than an independent certificate, but Oris does back it with the warranty. Fratello points out that the 10-year warranty covers performance, not just breakage.

Owner reports on watch forums are mostly in line with the spec, with many Aquis and Divers Sixty-Five owners describing a few seconds a day. There's the usual watch-to-watch variation, and a rate measured on a timegrapher at full wind won't always hold on day four or five as the spring runs down. That matters more here than with a 40-hour movement, because you'll actually leave it that long.

The magnetism work is the other half of the accuracy story. With a silicon escape wheel and pallet fork and non-ferrous arbors, Oris says the effect of a magnetic field is cut by more than 90% compared with a standard Swiss movement. In Laboratoire Dubois testing it drifted by less than 10 seconds a day after 2,250 gauss. The balance spring isn't silicon, so it isn't immune, but a laptop lid or phone case is much less likely to leave an Aquis running fast.

Reliability and servicing

The Calibre 400 has been in production since late 2020, and there's no widely reported systemic fault. The design choices point at longevity:

• Lower spring torque. Oris reduced the torque in the two mainsprings so the energy lasts longer and there's less load on the train.
• Slide-bearing rotor. Instead of a ball-bearing rotor that winds both ways, the rotor turns on a lubricated sleeve and winds in one direction only. Oris says that's simpler and wears less.
• 10 years on paper. Register the watch with MyOris and the warranty extends from two to ten years, with a matching recommended service interval. Accidental damage and water-resistance checks aren't covered.

The trade-off is the usual one for proprietary movements. An independent watchmaker can't buy Calibre 400 parts the way they can for a Sellita, so service goes through Oris. If you're keeping a watch for decades, that's worth knowing, although it's also true of Rolex, Omega or Tudor.

Quirks worth knowing

• One-way winding. The rotor only winds in one direction. It's normal and not a fault, but it means some wrist motion is wasted and a mechanical winder should be set to turn both ways, or in the direction Oris recommends.
• It takes a lot of winding. Two barrels hold five days of energy. From stopped, expect to give it plenty of crown turns, and don't expect a short morning's wear to fill it.
• Bigger movement. At 30 mm it's larger than the 25.6 mm Sellita SW200. That's why Calibre 400 cases can be a little thicker than their Sellita siblings.
• No reserve indicator. Apart from the "5 Days" text on some dials, nothing shows how much is left.
• Same watch, two movements. Aquis, Divers Sixty-Five and Big Crown models exist with both Sellita-based and in-house movements. Check the "01 400" in the reference before you buy.

How it compares

• Sellita SW200-1 (Oris 733): what the cheaper Aquis and Divers Sixty-Five use. Easy for any watchmaker to service, but about 38 to 41 hours of reserve, a third of the Calibre 400's.
• Sellita SH21: the Christopher Ward movement is the closest match on paper, also 120 hours at 4 Hz from two barrels, but a different design.
• Tudor MT5602: 70 hours and COSC certification, in the Black Bay. Less reserve, independent certification.
• Powermatic 80: 80 hours at a much lower price, but at 3 Hz and without the silicon escapement or long warranty.
• Longines L888: the obvious Swiss rival in the price bracket, with 72 hours.

Living with the 120-hour reserve

Five days changes how you use a watch. Take your Aquis Date off on Sunday evening, wear something else all week, and it's still running when you pick it up on Friday evening. In a two-watch rotation you can alternate weeks, or wear a Divers Sixty-Five at weekends and a work watch Monday to Friday, without ever resetting the time.

The catch is that the 120 hours only applies to a full spring. The Calibre 400's big barrels take longer to fill than a 40-hour Sellita's, and a watch you wore for an afternoon won't have five days in it. If you're about to rest it for most of a week, give it a proper wind first. Watch Winder counts down this 120-hour reserve for each watch you own and reminds you before it stops. To check a specific gap, try the "Will my watch stop?" calculator.

Verdict

The Calibre 400 is the reason to buy an in-house Oris over its Sellita twin. You get a five-day reserve, genuinely useful anti-magnetism, a tighter-than-COSC rate and a 10-year warranty, from a brand that doesn't charge Rolex or Omega prices. The trade-offs are modest: it winds one way, it isn't independently certified, the case can be a touch thicker, and servicing has to go through Oris. For anyone who rotates watches, that 120-hour reserve is the headline, and it lives up to it.

FAQ

How long does an Oris Aquis Date Calibre 400 run off the wrist?

About 120 hours, or five days, from a full wind. If it was only partly wound when you took it off, it will stop sooner.

Does the Oris Divers Sixty-Five Calibre 400 hack?

Yes. The Calibre 400 stops the seconds hand when you pull out the crown, so you can set the time to the second, and it can be wound by hand.

How accurate is the Oris Aquis Calibre 400?

Oris regulates the Calibre 400 to -3/+5 seconds a day, slightly tighter than the COSC range. It isn't COSC-certified, but Oris's warranty covers its performance.

How do I tell if my Oris Aquis has the Calibre 400 or a Sellita?

Look at the reference number. An 01 400 reference has the in-house Calibre 400, while 01 733 means the Sellita SW200-based Oris 733 with a much shorter reserve.

Why did my Oris ProPilot X stop after two days?

It almost certainly wasn't fully wound. The Calibre 400's two barrels need a lot of wear or crown winding to fill, so a lightly worn watch may have well under five days stored.

Is the Oris Calibre 400 really in-house?

Oris designed it entirely itself, but the parts are produced by a network of Swiss suppliers. Oris describes it as its own manufacture movement.

What does the Oris 10-year warranty cover?

If you register the watch with MyOris, Calibre 400 watches get a 10-year warranty that includes the movement's performance. Accidental damage and water-resistance checks aren't included, and Oris recommends servicing every 10 years.

Sources

• Oris: Calibre 400
• Fratello: Oris Calibre 400, anti-magnetic, 5 days power reserve and a 10-year warranty
• Monochrome: The new Oris Calibre 400 manufacture movement explained
• Monochrome: Oris Aquis Date Calibre 400 41.5mm
• Monochrome: Oris Divers Sixty-Five Calibre 400 38mm

Keeping it running

• On an average day an automatic gains roughly 4 hours of reserve per hour on the wrist, so about 30 hours of wear fills the Oris Calibre 400. Desk days charge more slowly.
• Most automatics can also be wound by the crown. If yours has stopped, a few dozen turns gets it going before you put it on.
• Off the wrist it stops about 120 hours after it was last full. Stopped sooner?
• On a watch winder, start at about 650 turns per day, both directions. Winder settings for every movement.
• If it does stop, don't set the date between 9pm and 3am. Check if it's safe.

Other 80-hour movements

Never let it stop

Watch Winder counts down the reserve of every watch you own and reminds you before one stops. It already knows the Oris Calibre 400: type your watch's name and the reserve fills itself in.

Manufacturer's published figure. Real reserve varies with the watch's age and service; check your manual.