The Apple Watch Series 12 is a watch for people who use an iPhone and want to run with it on every day. It went on sale on September 18, 2026, from JPY 71,800. Outdoor workouts last up to 10 hours, 25% longer than the previous generation. The case weighs 39.5g (46mm, aluminum). That is 2.5 sub-4 marathons' worth.
The Shoe Nerd's top pick
The Series 12 is a watch you choose by dividing 10 hours by your running time. At sub-4, 10 ÷ 4 is 2.5 runs. At sub-2:30, 10 ÷ 2.5 is 4 runs. If the result is above 1, the battery will last on race day. I run about 500 km a month and do not want to charge my watch over and over. So I split it: the Series 12 for people who stop at the marathon, the Ultra 4 for people who go on to 100km-class trails.
Key points
- Released Sep 18, 2026 · from JPY 71,800 · 10 hours outdoors
- JPY 71,000 cheaper than the Ultra 4, and the case is 23.5g lighter
- GPS is single-frequency L1. Suited to runners on open roads rather than between tall buildings
Is the Series 12 a buy? Divide the 10 hours by your running time
The Apple Watch Series 12 is a buy for people who use an iPhone and run with the watch on every day. The verdict first. Outdoor workouts last up to 10 hours, which is 2.5 sub-4 marathons' worth (10 ÷ 4).
That battery figure is 25% longer than the previous generation. So the previous one lasted 8 hours (10 ÷ 1.25). Short. This article lines the numbers up against 3 watches. Will it last on race day? That is the question that matters most.
The rivals are the Ultra 4, which came out in the same September, plus Garmin's Forerunner 170 and COROS's PACE 4 Pro. Those 3.
Series 12 weight, battery and price: the official numbers
| Item | Apple Watch Series 12 |
|---|---|
| Release date | Sep 18, 2026 (announced Sep 9) |
| Price (tax included) | From JPY 71,800 |
| Case weight | 39.5g (46mm, aluminum, GPS) / 32.2g (42mm) |
| Outdoor workout battery | Up to 10 hours |
| Everyday battery | Up to 24 hours (up to 38 hours in low power mode) |
| Charging | About 30 minutes to 80%. 15 minutes gives up to 12 hours of use |
| GPS | L1 high-precision GPS (GPS, GLONASS, Galileo, QZSS, BeiDou) |
| Display | Always-on OLED (LTPO3), up to 2,000 nits |
Divide the price by outdoor workout hours and you get JPY 7,180 per 1 hour (71,800 ÷ 10). The titanium case weighs 44.9g and the ceramic 51.3g, so they are heavier. It depends on the material.
Image: Rakuten Ichiba
Apple Watch Series 12
Lowest new priceJPY 71,472電子問屋 2号店
From Rakuten Ichiba search results, tax included. As of Oct 27. Check the shop's page for shipping, stock, color and size.
Buying from outside Japan? Sign up free for Rakuten Global Express (Rakuten's official forwarding service) and check out with its Japan warehouse address → full guide
What changed from the previous generation
Apple's announcement puts numbers on 3 differences. The outdoor workout battery is 25% longer. 15 minutes of charging gives 50% more use. And the aluminum model's glass is 60% tougher than the previous generation's.
Heart rate is measured every 5 seconds all day. The new "Readiness" gives a score from 0 to 10 and 4 suggestions (recover, pace yourself, ready, go for it). For runners, seeing a score every day quietly helps. It helps.
The gap between the previous generation's 8 hours and 10 hours is 2 hours (10 − 8). If your marathon finish time is 4 hours, that leaves 6 hours of margin. Big.
How does it differ from the Ultra 4, Forerunner 170 and PACE 4 Pro?
Scroll the table sideways →
| Watches | Price (tax included) | Weight | GPS battery | Per 1 hour |
|---|---|---|---|---|
| Apple Watch Series 12 | From JPY 71,800 | 39.5g (case) | Outdoors, up to 10 hours | JPY 7,180 |
| Apple Watch Ultra 4 | From JPY 142,800 | 63.0g (case) | Outdoors, up to 18 hours | JPY 7,933 |
| Garmin Forerunner 170 | JPY 47,800 | 41g | GPS mode, about 20 hours | JPY 2,390 |
| COROS PACE 4 Pro | JPY 69,960 | 43g (with band) | Normal mode, up to 60 hours | JPY 1,166 |
Garmin's and COROS's batteries last 2 to 6 times Apple's. The gap is big. On battery alone, there is no contest. The Series 12 does not fight on battery. It fights on the link to your iPhone and everyday ease of use.
The gap to the Ultra 4 is JPY 71,000 in price (142,800 − 71,800), 23.5g in case weight (63.0 − 39.5), and 8 hours of outdoor battery (18 − 10). Details are in the Ultra 4 review.
What the Numbers Say About Running Style and Pace
10 hours of battery is 2.5 runs at sub-4 pace, about 2.9 at sub-3:30 and about 3.3 at sub-3. Even someone who takes 6 hours to finish gets 1.7 runs (10 ÷ 6).
A 39.5g case and 9.7mm thickness read as a build suited to wearing on your wrist every day while you run. Light and thin. Apple does not say what level of runner it is for, so this is my own reading of the numbers.
The GPS is single-frequency L1. Unlike the dual-frequency Ultra 4, expect your position to wander on some days between tall buildings or under thick trees. On open riverbanks or park loops, many people will not mind. That is the dividing line.
Image: Rakuten Ichiba
Apple Watch Series 12
Lowest new priceJPY 71,472電子問屋 2号店
From Rakuten Ichiba search results, tax included. As of Oct 27. Check the shop's page for shipping, stock, color and size.
Buying from outside Japan? Sign up free for Rakuten Global Express (Rakuten's official forwarding service) and check out with its Japan warehouse address → full guide
What I like
What I like is how easy it is to use every day. Heart rate every 5 seconds all day, and sleep and your readiness score in the same watch. Easy. Recovery after a run connects on one screen. Handy. Running features are in too: pacer, course, automatic track detection and running metrics.
Things to watch
This part is so-so. 10 hours outdoors is not enough for a 100km-class trail or a triathlon with a long cutoff. Not enough. If you run that far, there is also the Ultra 4, Garmin or COROS. It needs iPhone 11 or later and iOS 27 or later.
Who is the Apple Watch Series 12 for?
- People who use an iPhone and want to run with the watch on every day
- People whose distances top out at the marathon
- People who want sleep and recovery numbers in the same watch
To line it up against other watches, see the 12 running watches article. For Garmin's entry model, see the Forerunner 170 review.
Price and where to buy
The price is in the table above. Wear it every day for 3 years and it is about JPY 66 a day (71,800 ÷ 1,095). On Rakuten Ichiba, the Rakuten Mobile official store and others list it. The price changes with case material and band, so first decide the case size (42mm or 46mm).
Image: Rakuten Ichiba
Apple Watch Series 12
Lowest new priceJPY 71,472電子問屋 2号店
From Rakuten Ichiba search results, tax included. As of Oct 27. Check the shop's page for shipping, stock, color and size.
Buying from outside Japan? Sign up free for Rakuten Global Express (Rakuten's official forwarding service) and check out with its Japan warehouse address → full guide
About the writer and sources
Written by a shoe nerd who runs about 500 km a month, runs a marathon best under 2:30, and also races trail and triathlon. I re-read the numbers on Apple's Japan official pages on October 26. Last updated October 27.
FAQ
When was the Apple Watch Series 12 released?
It went on sale on Sep 18, 2026. It was announced on Sep 9, and prices start at JPY 71,800 (tax included).
Is the Apple Watch Series 12's battery enough for a marathon?
Outdoor workouts last up to 10 hours. That is 2.5 runs at a sub-4 marathon pace, and 1.7 runs even for someone who needs 6 hours to finish.
How does the Apple Watch Series 12 differ from the Ultra 4?
The Ultra 4 costs JPY 71,000 more, its case is 23.5g heavier, and its outdoor battery lasts 8 hours longer. On GPS, the Ultra 4 uses 2 frequencies and the Series 12 uses 1.
