Garmin Forerunner 55 vs Garmin Instinct E 45mm
Garmin Forerunner 55 (2021, listed at $199) and Garmin Instinct E 45mm (2025, listed at $249.99) are both sport watches, so the choice comes down to specifics.
Specs last updated · table prices are list prices; each card shows Amazon's current price when available
Garmin Forerunner 55
Beginner-friendly running GPS — coach-style plans, 14-day battery, refreshingly simple UI.
Garmin Instinct E 45mm
Entry-level rugged Garmin: MIL-STD-810 build, 10 ATM, multi-GNSS GPS with compass and altimeter, and up to 16 days per charge.
The verdict
On the numbers we track, Garmin Forerunner 55 wins on weight (37 g vs 48 g) and price ($199 vs $249.99); Garmin Instinct E 45mm wins on battery life (16 days vs 14 days), tracked features (3 vs 1) and water rating (10ATM vs 5ATM).
Bottom line: on raw specs the Garmin Instinct E 45mm leads 3 to 2, but five spec categories are only a starting point. Match it to your phone, your main sport and your budget before you decide, or run the free quiz to see how each ranks for your answers.
Spec by spec
| Spec | Garmin Forerunner 55 | Garmin Instinct E 45mm |
|---|---|---|
| Battery (rated) | 14 days | 16 days |
| Weight | 37 g | 48 g |
| List price | $199 | $249.99 |
| Water rating | 5ATM | 10ATM |
| Tracked features | 1 | 3 |
| Case size | 42 mm | 45 mm |
| Display | MIP | MIP |
| Works with | both iPhone and Android | both iPhone and Android |
| Listed best for | running | outdoor adventure and running |
| Released | 2021 | 2025 |
Trophy marks the better value on the five measurable specs. Battery is the manufacturer's rating, not our test. How we score is on the methodology page.
Feature overlap
Both have (1)
- built-in GPS
Only Garmin Forerunner 55 (0)
Nothing unique.
Only Garmin Instinct E 45mm (2)
- blood-oxygen (SpO₂)
- swim tracking
Which one should you pick?
Pick the Garmin Forerunner 55 if…
- You want to spend less: it lists for $50.99 less.
- You want a lighter watch: 37 g vs 48 g.
- You might switch phones: it works with both iPhone and Android, the Garmin Instinct E 45mm only works with Android.
Skip it if…
- • You want a bright, vivid AMOLED screen — this one uses a lower-power display.
Pick the Garmin Instinct E 45mm if…
- You want fewer charges: about 16 days per charge vs 14 days.
- You need blood-oxygen (SpO₂) and swim tracking, which the Garmin Forerunner 55 does not list.
- Your main use is outdoor adventure: it is listed for that and the Garmin Forerunner 55 is not.
- You might switch phones: it works with both iPhone and Android, the Garmin Forerunner 55 only works with Android.
- You want the newer model (2025 vs 2021).
Skip it if…
- • You want a bright, vivid AMOLED screen — this one uses a lower-power display.
Frequently asked questions
Which has better battery life, the Garmin Forerunner 55 or the Garmin Instinct E 45mm?
The Garmin Instinct E 45mm has the longer rated battery life: about 16 days per charge against 14 days. These are manufacturer ratings; heavy GPS, always-on display and cellular use will cut both.
Which is cheaper, the Garmin Forerunner 55 or the Garmin Instinct E 45mm?
The Garmin Forerunner 55 has the lower list price: $199 against $249.99 in our database. List prices change often, so check Amazon for today's price.
Do the Garmin Forerunner 55 and Garmin Instinct E 45mm work with iPhone and Android?
Yes, they have the same phone support: both iPhone and Android.
Which is better for swimming, the Garmin Forerunner 55 or the Garmin Instinct E 45mm?
Garmin Forerunner 55: 5ATM is suitable for showering and pool swimming, but not for high-speed water sports or diving. Garmin Instinct E 45mm: 10ATM is suitable for swimming and surface water sports. It is not a dive rating unless the maker says so.
Not sure either is right for you?
Nine questions about your phone, sport, wrist and budget, scored against all of our watches with the reasoning shown.
Take the free quiz