Apple Watch Series 12 and Ultra 4: what's new, and the band mistake everyone makes
New Apple Watch just dropped. Series 12 and Ultra 4 are in stores now. Before you order a new band, there's one sizing trap worth knowing about — it catches almost everyone upgrading from an older watch.
What's actually new
Apple Watch Series 12
- Same 42mm / 46mm case sizes as before
- Ceramic Shield 2 glass — about 60% tougher than the old screen
- Faster S11 chip, sharper health tracking
- New colours: Jet Black, Silver, Rose Gold, Space Gray, plus a fresh Dark Bronze finish
- Ceramic "Edition" case is back (white or blue) for the first time since 2019
Apple Watch Ultra 4
- Still 49mm titanium, now nearly half recycled material
- Battery life pushed past two days
- New Max Extended GPS mode for long days outdoors
Solid upgrades. Not the part that trips people up.
The band trap: read this before you buy a strap
Here's the confusing part. "42mm" has meant two totally different watches.
- Series 1–3: the 42mm case was the large size.
- Series 10, 11, 12: 42mm is now the small size, with narrower lug spacing.
Same number. Different watch. Different fit.
So if your old watch is a Series 1, 2 or 3, your old 42mm band will not fit a new 42mm Series 12. It'll actually fit the 46mm instead — because your old large 42mm and the new large 46mm share the same width.
Quick way to check yourself:
- Coming from Series 1–3 → look for bands sized 44mm/45mm/46mm
- Coming from Series 4–9 or SE → your old bands carry straight over (40/41mm → new 42mm, 44/45mm → new 46mm)
- Coming from Series 10 or 11 → no change at all, your bands already fit
The good news: the connector itself hasn't changed since 2015. Once you're in the right size group, everything clicks in the same way it always has. It's a labelling problem, not a hardware one.
Our advice: ignore the millimetre number on your old watch box. Shop by size group, not by label. Every band on ohmyband.com is sorted this way, and our sizing guide will confirm your fit in under a minute.
New colours this season
Apple's own lineup leans warm and autumnal this year — Navy Blue, Magenta, Olive, Burgundy, Wildflower Blue, plus a new translucent Ocean finish on the Ultra bands.
We're not chasing the same palette. We'd rather give you something Apple doesn't sell at all:
- Miroir and Serene — quiet stainless steel, goes from a run to dinner without missing a beat
- Éclat — chunkier chain-link, for when Ultra 4's size on your wrist deserves some presence
- Ruban and Épure — the ones we'd hand you if you just want it to fit right and look sharp
All sized correctly for the new 42mm and 46mm Series 12 cases, and for Ultra 4's 49mm, from day one.
Upgrading this month?
Get the size right, and a good band will outlast this watch and the next one. That's the whole trick.