Between the Watch Series 11 (45mm) and OnePlus Watch 3, the Watch Series 11 (45mm) comes out ahead in weight and peak brightness, while the OnePlus Watch 3 wins on battery life. Overall, the Watch Series 11 (45mm) scores 60.5 and the OnePlus Watch 3 scores 53.9 on our Mars Score.
Which should you buy?
The Watch Series 11 (45mm) edges ahead on the Mars Score (60.5 vs 53.9), but the 6.6-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the Watch Series 11 (45mm) if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. The biggest gaps in its favor are weight, peak brightness, display size, among others.
Pick the OnePlus Watch 3 if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. Its strongest claims are battery life.
Both ship with comparable ecg, spo2, water resistance, so those specs don't separate the two — focus on the differences below.
Bottom line: the Watch Series 11 (45mm) is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Apple - Watch Series 11 (45mm) wins
- ▲Weight — 43.00 g less. 38 vs 81.
- ▲Peak brightness — 36.36% more. 3000 nits vs 2200 nits.
- ▲Display size — 28.00% more. 1.92 " vs 1.5 ".
- ▲Has Cellular.
Why OnePlus Watch 3 wins
- ▲Battery life — 233.33% more. 120 h vs 36 h.
Spec comparison
Design
| Spec | Apple - Watch Series 11 (45mm) | OnePlus Watch 3 |
|---|---|---|
| Case size | 45 mm | 46.5 mmlead |
| Weight | 38 glead | 81 g |
| Case material | aluminum | stainless steel |
| Water resistanceⓘ | 5 ATM | 5 ATM |
Display
| Spec | Apple - Watch Series 11 (45mm) | OnePlus Watch 3 |
|---|---|---|
| Display size | 1.92 "lead | 1.5 " |
| Always-on display | true | true |
| Peak brightnessⓘ | 3000 nitslead | 2200 nits |
Health & Fitness
| Spec | Apple - Watch Series 11 (45mm) | OnePlus Watch 3 |
|---|---|---|
| ECG | true | true |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Apple - Watch Series 11 (45mm) | OnePlus Watch 3 |
|---|---|---|
| Battery life | 36 h | 120 hlead |
| GPS | true | true |
| Cellular | truelead | false |
| NFC | true | true |
| OS | watchOS | WearOSlead |
Frequently asked
Which has longer battery life, Watch Series 11 (45mm) or OnePlus Watch 3?+
OnePlus Watch 3 lasts 120h vs 36h.
Do Watch Series 11 (45mm) or OnePlus Watch 3 support ECG?+
Both support ECG.
Which has cellular, Watch Series 11 (45mm) or OnePlus Watch 3?+
Watch Series 11 (45mm) offers a cellular variant; OnePlus Watch 3 is Wi-Fi only.
Spec-level deep dives
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