Some links on this page are affiliate links: we may earn a commission, at no extra cost to you. As an Amazon Associate I earn from qualifying purchases. How this works
Amazfit T-Rex 3 Pro (48 mm) vs Garmin fenix 8 Pro AMOLED (47 mm)
The specs that matter for triathlon, side by side, from each maker’s own published figures.
| Spec | Amazfit T-Rex 3 Pro (48 mm) | Garmin fenix 8 Pro AMOLED (47 mm) |
|---|---|---|
| GPS battery | 38 h | 44 h |
| Smartwatch battery | 25 days | 15 days |
| Triathlon / multisport mode | Yes | Yes |
| Onboard maps | Yes | Yes |
| Open-water GPS (our rating) | 4 / 5 | 5 / 5 |
| Weight | 52 g | 77 g |
| Screen | AMOLED 1.5in (480x480) | AMOLED 454x454 |
| Price | ~$399.99 | ~$1,099.99 |
Open-water GPS is our 1–5 rating from the satellite systems each maker lists: multi-band receivers score 5. Everything else is the maker’s own figure.
Which should you pick?
Amazfit
Pick the T-Rex 3 Pro (48 mm) if…
- you want the longer smartwatch battery: 25 days vs 15 days
- you want the lighter one: 52 g vs 77 g
Garmin
Pick the fenix 8 Pro AMOLED (47 mm) if…
- you want the longer GPS battery: 44 h vs 38 h
- you want better open-water GPS (our rating): 5 / 5 vs 4 / 5
Specs from the makers’ own pages: Amazfit, Garmin.
Not sure either is right?
Free tool
Triathlon Watch Comparison
Battery life, open-water GPS and maps across the watches triathletes buy.
Try the tool →
Free tool
Triathlon watches, compared
Every product in this category in one spec table, plus 820 head-to-heads.
See them all →