Apple Watch Ultra 4 and Apple Watch Series 12 share the S11 chip, the same Health Sensing System, the same Readiness app and the same 64GB of storage, so this is not a health decision. Three published numbers settle it instead: the wrist range each case is designed to fit, how many hours the watch keeps recording a workout, and what each one costs across 24 months.
Series 12 starts at $399 in a 42mm or 46mm case and three materials. Ultra 4 is one 49mm titanium case at $799. Everything below comes from Apple’s tech specs and store pages.
The short version
| Item | Apple Watch Series 12 | Apple Watch Ultra 4 |
|---|---|---|
| Starting price | From $399 | From $799 |
| Case | 42mm or 46mm; aluminum, titanium or ceramic | 49mm Grade 5 titanium, natural or black |
| Chip and storage | S11, 64GB | S11, 64GB |
| Battery, normal use | Up to 24 hours | Up to 50 hours |
| Outdoor workout | Up to 10 hours | Up to 18 hours |
| Water resistance | 50 m, IP6X | 100 m, IP6X, EN13319 scuba to 40 m |
| Satellite | No | Emergency SOS, Messages and Find My, two years included |
| Availability | In stores September 18 | In stores September 18 |
Number one: the wrist range Apple publishes
| Measurement | Series 12, 42mm | Series 12, 46mm | Ultra 4 |
|---|---|---|---|
| Case, height x width x depth | 42 x 37 x 9.7 mm | 46 x 40 x 9.7 mm | 49 x 44 x 12 mm |
| Weight | 32.2 g, aluminum GPS | 39.5 g, aluminum GPS | 63.0 g, natural titanium |
| Wrist fit | 130 to 200 mm | 140 to 245 mm | 130 to 210 mm |
| Display | 374 x 446 px, 2000 nits | 416 x 496 px, 2000 nits | 422 x 514 px, 3000 nits |
The surprise in Apple’s own figures is that Ultra 4 is rated to fit wrists from 130 mm, the same lower bound as the smallest Series 12. A small wrist does not rule it out on Apple’s numbers. What you notice instead is depth and mass: 12 mm against 9.7 mm, and 63.0 g against 32.2 g, which is nearly double the weight of the 42mm aluminum model. Ceramic Series 12 cases are the heavy end of that line at 41.7 g to 52.9 g, and they measure 43mm and 47mm rather than 42mm and 46mm.
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Number two: how long your longest session runs
Series 12 is rated for up to 10 hours of outdoor workout. Ultra 4 is rated for up to 18 hours of outdoor workout, up to 25 hours in Extended Workout mode, and up to 45 hours in a new Max Extended Workout mode that drops to one-second GPS intervals and which Apple aims at 100-mile races.
- Series 12 uses Precision L1 GPS; Ultra 4 uses precision dual-frequency GPS, which Apple calls the most accurate on-device GPS in a sports watch
- Series 12 is rated to 50 m; Ultra 4 to 100 m, with EN13319 recreational scuba to 40 m and a depth gauge Apple rates to within one meter
- A 15-minute charge is quoted at 12 hours on Series 12 and 18 hours on Ultra 4; 80 percent takes about 30 minutes on Series 12 and about 45 on Ultra 4
- Ultra 4 peaks at 3000 nits against 2000, and is tested to MIL-STD 810H
If your longest recorded activity is a 90-minute gym session or a half marathon, Series 12 clears it several times over. If you race for longer than 10 hours, or dive, the Ultra numbers are the whole argument.
Number three: what each costs over 24 months
| Route | Series 12 | Ultra 4 |
|---|---|---|
| Buy outright | From $399 | From $799 |
| Apple Upgrade lease | $11.99 a month over 24 months | $24.99 a month over 24 months |
| Lease payments over 24 months | $287.76 | $599.76 |
| Gap | $400 more outright, $312 more across the lease |
The 24-month totals are our arithmetic on Apple’s published monthly figures. Note the catch: Apple describes these as Apple Upgrade lease payments, not installments toward ownership, and it has not published the end-of-term terms in this release, so a lease total is not a purchase price. Both $399 and $799 are starting prices for a base configuration, and Apple has not published titanium, ceramic or cellular prices for Series 12.
What is identical on both
The S11 chip with its Secure Exclave, 64GB of storage, heart rate measured every five seconds, HRV measured every five minutes, Recovery HRV, the Readiness score, the Steps complication, Audio Intelligence and watchOS 27, which ships on September 14 alongside iOS 27, are the same on each. Apple applies the same heart rate accuracy claim to both. Series 12 is the only one of the two offered in aluminum or ceramic, and Ultra 4 is the only one with satellite messaging.
What Apple has not said
Apple has not published band prices, cellular or premium-material prices for Series 12, Hermès pricing for either watch, or any Apple Watch trade-in value. It has not published a Series 12 Extended Workout mode, so treat the 10-hour outdoor workout figure as the ceiling. Satellite terms beyond the included two years are not detailed in the release, and the September 9 event did not add a cheaper option, since no new Apple Watch SE was announced.
Pre-orders for both watches are open now, and both reach stores on Friday, September 18. watchOS 27 ships on Monday, September 14, four days ahead of the hardware.
