The Apple Watch Ultra 4 is a watch for people who use an iPhone and want to track a full marathon and triathlon with 1 watch. The deciding point is up to 18 hours on the normal outdoor workout setting. Released Sept 18, 2026, from JPY 142,800, a titanium case of 63.0g, water resistant to 100m.
The Shoe Nerd's top pick
Divide the time limit of your race by "18" before buying the Ultra 4. If the result is under 1, it tracks to the finish with no setting dropped. Full marathons and long triathlons fall here. A 100km trail goes over 1, and beyond that it costs a setting that cuts what is recorded. So I recommend this watch only to road and triathlon people.
Key points
- From the previous Ultra 3, normal battery goes 42 → 50 hours (+8 hours), and time from a 15-minute charge 12 → 18 hours. The case is 1.4g heavier
- The gap from the Series 12 is JPY 71,000. Outdoor workout time is 10 and 18 hours, a 8-hour gain
- The 45 hours of "Long Workout (Max)" is a figure with alerts and splits turned off. It falls 30 minutes short of FUJI100mi's 45 hours 30 minutes
Is the Ultra 4 worth buying: the same watch has 3 battery figures
The Apple Watch Ultra 4 is a buy for people who use an iPhone and enter full marathons and triathlons. With up to 18 hours on the normal setting, it tracks even a long triathlon with a 13-hour time limit without dropping settings.
For outdoor workout battery, 18, 25 and 45 hours are the 3 official figures. On this site too, the article on 12 running watches calculates with 18 hours and the fall new releases article with 25 hours. It is not a contradiction; the settings differ. 18 hours is the normal setting, and 25 hours is the figure for the "Long Workout" setting.
Which figure applies to your race decides whether it is enough.
Ultra 4 weight and battery? The official numbers
| Item | Apple Watch Ultra 4 |
|---|---|
| Release date | Sep 18, 2026 (announced Sep 9) |
| Official price | From JPY 142,800 |
| Weight | 63.0g (natural) / 63.1g (black) |
| Case size | 49mm tall x 44mm wide x 12mm thick |
| Screen type | Always-on OLED (LTPO3 OLED), sapphire crystal |
| Screen size | Display area 1,245mm², 422 x 514 pixels |
| Screen brightness | Up to 3,000 nits |
| Battery with GPS on | Up to 18 / 25 / 45 hours (changes by setting) |
| Everyday battery | Up to 50 hours (up to 84 hours in low power mode) |
| Water resistance | 100m water resistance, diving to 40m, dust resistance IP6X |
| Maps | Yes (offline maps downloaded on the iPhone sync to the watch) |
| GPS | Dual-frequency (GPS, Galileo, QZSS, BeiDou) |
| Storage | 64GB |
Divide the price by the case weight and it is about JPY 2,267 per gram (142,800 ÷ 63.0). When lining it up with running-only watches, first remember this weight is without the band.
Image: Rakuten Ichiba
Apple Watch Ultra 4
Lowest price on Rakuten Ichiba: JPY 139,800 (as of 10/13). Prices change daily.
RecommendedSee it on Yahoo! Shopping JapanSee it on Rakuten IchibaWhat each of the 3 battery figures cuts
This is the easiest part of the Ultra 4 spec table to miss. The longer the time of a setting, the less the watch does. I put the notes from the spec page into a table.
| Setting | Hours | What becomes unavailable | Per 1 hour |
|---|---|---|---|
| Normal outdoor workout | Up to 18 hours | None | JPY 7,933 |
| Long Workout | Up to 25 hours | Running form metrics (low power mode turns on automatically) | JPY 5,712 |
| Long Workout (Max) | Up to 45 hours | Alerts and splits, some metrics | JPY 3,173 |
From 18 to 45 hours, the time grows 2.5 times (45 ÷ 18). In exchange, in the longest setting, the 1km splits and pace alerts stop. The announcement says GPS still measures every second in this setting.
In other words, 45 hours is a figure where "the route remains, but the information you can see while running shrinks." Read it in the same row as other companies' catalog "battery-extending settings."
Ultra 4 vs Ultra 3: what changed from the previous generation
The previous generation is the 2025 Apple Watch Ultra 3. I lined up Apple Support's technical specs page and the Ultra 4 spec page.
| Item | Ultra 3 | Ultra 4 | Difference |
|---|---|---|---|
| Case weight (natural) | 61.6g | 63.0g | +1.4g |
| Everyday battery | Up to 42 hours | Up to 50 hours | +8 hours |
| Low power mode | Up to 72 hours | Up to 84 hours | +12 hours |
| Time from a 15-minute charge | Up to 12 hours | Up to 18 hours | +6 hours |
| Long Workout | 20 hours (calculated) | Up to 25 hours | +5 hours |
| Chip | S10 | S11 | 1 generation |
| Case and screen | 49 x 44 x 12mm, 1,245mm², 3,000 nits | Same | Unchanged |
The normal battery grew 8 hours, about 19% (8 ÷ 42). Low power mode about 17% (12 ÷ 72). Not one number moved for case size, screen size or brightness.
Same-size box, only the battery grew. The weight gain is 1.4g, about 2% (1.4 ÷ 61.6). This generation change is one that extended the battery without changing the shape.
The other big one is charging. The time from 15 minutes of charge went from 12 to 18 hours. That is 1.5 times (18 ÷ 12). 18 hours is the same number as the normal outdoor workout limit.
The announcement also describes a new sensor that measures heart rate every 5 seconds and a "readiness" score from 0 to 10 for how prepared the body is. How accurate the numbers are cannot be compared from the official spec table, so I do not cover it here.
Image: Rakuten Ichiba
Apple Watch Ultra 3 (previous generation)
Lowest price on Rakuten is JPY 131,890 (as of 10/13), ranging up to JPY 169,200 depending on the shop. Prices change daily.
RecommendedSee it on Yahoo! Shopping JapanSee it on Rakuten IchibaSeries 12 and SE 3 compared (sibling models)
What is lined up on Apple's purchase page now is 3: the Ultra 4, Series 12 and SE 3.
| Ultra 4 | Series 12 | SE 3 | |
|---|---|---|---|
| Official price | From JPY 142,800 | From JPY 71,800 | From JPY 41,800 |
| Case | 49mm | 46mm / 42mm | 44mm / 40mm |
| Everyday battery | Up to 50 hours | Up to 24 hours | Up to 18 hours |
| Brightness | 3,000 nits | 2,000 nits | 1,000 nits |
| Water resistance | 100m | 50m | 50m |
Difference from the Series 12: The gap is JPY 71,000 (142,800 − 71,800). Outdoor workout is 8 hours longer (18 − 10). That works out to JPY 8,875 for each extra hour (71,000 ÷ 8). The case is 23.5g heavier (63.0 − 39.5).
With 10 hours, 1 and 2/3 full marathons of 6 hours fit (10 ÷ 6 = 1.67). If you only race on the road, the Series 12's battery is enough.
- Up to a full marathon. Lighter is better → Series 12
- Long triathlon, swimming in the sea, want dual-frequency GPS → Ultra 4
- Distance and time are enough → SE 3 (read the outdoor workout time officially before buying)
Image: Rakuten Ichiba
Apple Watch Series 12
Lowest price on Rakuten is JPY 71,728 (as of 10/13), ranging up to JPY 159,800 depending on the shop. Prices change daily.
RecommendedSee it on Rakuten IchibaWhat I like
There are 2 escape routes for battery. If 18 hours is not enough, 25 hours; if still not enough, 45 hours. What gets cut is set per tier, so before a race you can choose for yourself "how much to give up."
15 minutes of charging reaches 1 workout. Up to 18 hours from 15 minutes. That is 1.5 times the previous generation. 0% to 80% is written as about 45 minutes. Making up for a morning you forgot to charge got faster in this generation.
It handles swimming, cycling and running with 1 watch. The product page explains a multisport mode that switches swim, bike and run automatically and records each leg. Water resistance is 100m. For people who enter triathlons, this is where the price gap to the Series 12 has a reason.
The screen brightness is the top in the table. The maximum 3,000 nits is 1.5 times the Series 12 and 3 times the SE 3. It is a watch you read numbers on in sunlit road conditions, so this gap is not decoration.
Maps and navigation are complete. You can send a route made on the iPhone to the watch and get turn-by-turn guidance. Offline maps are downloaded on the iPhone and synced. Even without signal, backtrace to return along the path you took works.
Things to watch
18 hours is on the short side among running-only watches. In this site's table of 12 watches, it is in the bottom rows. The price per hour of battery is JPY 7,933, the highest in the table. It is not a watch you buy for battery.
63.0g is without the band. Most dedicated watches are in the 40 to 50g range with the band. The weight on your wrist differs more than the table's numbers. From my feel running a full marathon in 2:30, what I want from a watch in road races is lightness first, and that is where the Ultra 4 cannot win.
Long settings reduce the information while you run. At the 45-hour setting, splits and alerts stop. For someone who wants to advance watching pace per segment, it will not be 45 hours as in the number.
You need an iPhone. It needs an iPhone 11 or later running iOS 27 or later. Android users are out of the candidates from the start.
Some announced features are not yet usable in Japan. The hypertension pattern notification is written as not available in Japan in the initial stage. Siri AI in Japanese is scheduled to be added in October (month 10).
Is the Ultra 4 battery enough for races? Who does it fit?
Divide the race time limit by the battery hours. If under 1, it is enough. The time limits are numbers I read from official entry guides in this site's race calendar and the mandatory gear article.
Scroll the table sideways →
| Racing | Cutoff | 18 hours | 25 hours | 45 hours |
|---|---|---|---|---|
| Marathon | 6 hours | Enough | Enough | Enough |
| Long triathlon (Miyakojima) | 13 hours | Enough | Enough | Enough |
| Izu Trail Journey 70k | 14 hours | Enough | Enough | Enough |
| OSJ KAMI100 100K | 25 hours | Not enough | Just enough | Enough |
| Tokyo100 (101km) | 30 hours | Not enough | Not enough | Enough |
| FUJI100mi | 45 h 30 min | Not enough | Not enough | 30 minutes short |
Full marathon: enough. It holds 3 races of 6 hours on the normal setting (18 ÷ 6). There is no reason to drop the setting.
Long triathlon: enough. On Miyakojima with a 13-hour time limit, 5 hours remain (18 − 13). Swim 3km, bike 123km and run 42.195km can be covered on the normal setting. Distance categories are collected in the triathlon distance article.
100km trail: not enough on the normal setting. In a 25-hour race, it falls 7 hours short (25 − 18). The 25-hour setting is exactly on the number, but with zero to spare. In reality you would drop to the 45-hour setting and give up splits and alerts.
- Good fit: Someone who uses an iPhone and enters full marathons and triathlons. Someone who wears the same watch on non-running days too.
If trails over 100km are your main ground, or lightness is first, there are other ways to choose. If you have no complaint about the Series 12's 10 hours or the Ultra 3, wearing it out first is still in time.
Price and where to buy
| Model | Official price | Rakuten price range |
|---|---|---|
| Apple Watch Ultra 4 | From JPY 142,800 | JPY 139,800 |
| Apple Watch Series 12 | From JPY 71,800 | JPY 71,728–159,800 |
The official prices are shown with "from." The purchase page lines up the Trail Loop, Alpine Loop, Ocean Band and Milanese Loop.
The yardstick for choosing the previous generation is the 5 differences in the table: 8 hours of normal battery, 12 hours of low power mode, 6 hours from a 15-minute charge, 5 hours of Long Workout, and 1.4g of weight. The case and screen are the same, so you do not lose out on looks.
When buying on Rakuten, look at the "Ultra 4," "Ultra 3" and "Ultra 2" numbers in the product name. 3 generations line up at the same time.
Image: Rakuten Ichiba
Apple Watch Ultra 4
Lowest price on Rakuten Ichiba: JPY 139,800 (as of 10/13). Prices change daily.
RecommendedSee it on Yahoo! Shopping JapanSee it on Rakuten IchibaFAQ
Which setting should I use to track a full marathon on the Apple Watch Ultra 4?
The normal setting is enough. The maximum 18 hours is 3 times a 6-hour time limit. Switching to "Long Workout" disables running form metrics. From the battery math, there is no reason to drop to that setting for a full marathon.
Can the Ultra 4 track a 100-mile race?
It cannot finish FUJI100mi. Even the longest setting, up to 45 hours, falls 30 minutes short of FUJI100mi's 45 hours 30 minutes time limit (45.5 − 45). For the Shinetsu Five Mountains 100 miles (33 hours), the 45-hour setting leaves 12 hours to spare. In both cases, splits and alerts stop. For someone who wants to track 100 miles without dropping settings, the 65- and 80-hour models in the article on 12 watches fit.
Can the Apple Watch Ultra 4 be used with Android?
No. It needs an iPhone 11 or later (or an iPhone SE 2nd generation or later) running iOS 27 or later. An Android user choosing from the same period's new releases would pick a dedicated watch like the SUUNTO Run 2.
How do the Apple Watch Ultra 4 and Ultra 3 differ?
The normal battery is 8 hours longer, and the time from a 15-minute charge is 6 hours longer. The case size and screen are the same, and the weight is 1.4g more.
