Garmin

Unisex

1.1 in. (27.5 mm) diameter

218 x 218 pixels

Sunlight-visible, transflective memory-in-pixel (MIP)

39 g

• Get an overview of your sleep, HRV status and daily workout with morning report.
• Charge less, train more with up to 12 days of battery life in smartwatch mode and up to 26 hours in GPS mode.
• Push your limits with a built-in triathlon feature and 30+ activity profiles.
• Plan your strategy with daily suggested workouts, course details and more on the race widget.
• Utilize a full suite of advanced metrics and training tools to reach your goals.
• Pay for your post-workout coffee with Garmin Pay™ contactless payments(1) — and listen to music on the go.

READY FOR THE LONG RUN
Get an uninterrupted picture of your daily health and nightly sleep with up to 12 days of battery life in smartwatch mode and up to 26 hours in GPS mode.
MUSIC ON YOUR WRIST
Download up to 500 songs plus playlists from your Spotify, Deezer or Amazon Music accounts (subscription required).
(ALMOST) AS LIGHT AS A FEATHER
With its sleek design and 1.4 oz weight, you’ll almost forget you’re wearing Forerunner 255S — even when you’re asleep.
SWEAT-READY MATERIALS
Featuring easy-to-use buttons and a silicone band, this watch is ready to wear — and tear — with durable Corning® Gorilla® Glass 3.

MORNING REPORT
Receive an overview of your sleep, recovery and training outlook as soon as you wake up — alongside HRV status and weather. You can even customize your report to show you what you want to see.
HRV STATUS
Gain a deeper understanding of your overall health, recovery and training performance through heart rate variability while you sleep, based on technology developed by Garmin's Firstbeat Analytics™ team.
BUILT-IN SPORTS APPS
Tap into 30+ built-in activities, including the triathlon and open-water swimming profiles — new to the Forerunner 255 series. For races and brick workouts, transition to the next activity with a single button press.
RACE WIDGET
Get ready for your next race with training tips, personalized daily suggested workouts and completion time predictions based on course details, weather and performance.
DAILY SUGGESTED WORKOUTS
View your entire week of daily suggested workouts, which adapt after every run to match your performance and recovery as well as the races coming up in your Garmin Connect™ smartphone app calendar.
GARMIN COACH
Free adaptive training plans include 5K, 10K and half-marathon programs, featuring guidance from expert coaches that adapt to you and your goals.
RUNNING POWER
When using a Running Dynamics Pod or HRM-Pro™ monitor, get a continuous measurement on your wrist of how much power you’re applying to the road as you run, so you can manage your effort.
RECOVERY TIME
Know how long to recover before your next high-effort workout based on your latest training as well as overall stress, sleep and daily activities outside of workouts.
PACEPRO™ FEATURE
To help you plan your race day strategy, this feature offers GPS-based pace guidance for a selected course or distance, so you can tailor your efforts to what’s ahead.
TRAINING STATUS
Using new indicators such as HRV status, your recent exercise history and performance, get an easy insight into your overall effort — and whether you’re training productively, peaking or strained.
ACUTE LOAD
See your training history, and compare the intensity of your recent workouts to the optimal range to help improve your fitness.
TRAINING EFFECT
See how your workouts influence your endurance, speed and power with aerobic and anaerobic training effect feedback.
PERFORMANCE CONDITION
While you run, get an analysis of your pace and heart rate for a real-time assessment of your current ability to perform.
RUNNING DYNAMICS
When using a Running Dynamics Pod or HRM-Pro monitor, the Forerunner 255S measures crucial running metrics such as cadence, stride length, ground contact time and balance, and more — while comparing to others in the Garmin Connect app.
COURSES
Create or find existing courses in the Garmin Connect app, so you’ll never run out of places to run. Or plan one on other platforms such as Strava and Komoot, then automatically sync them to your Forerunner.
VISUAL RACE PREDICTOR
Based on your running history and overall fitness level, get an estimate of what your pace could be for a 5K, 10K — or even a marathon. Plus, trend data highlights your training’s impact over time.
CROSS-TRAINING
Mix up your training with different types of workouts. Free HIIT, strength, cardio, yoga and Pilates workouts come preloaded on the watch, and you can download more from the Garmin Connect app.

WRIST-BASED HEART RATE
The watch constantly samples your heart rate(2) with Garmin's latest-generation heart rate sensor and will alert you if it stays too high or too low while you’re at rest. It also helps gauge how hard you work during activities — even while swimming.
BODY BATTERY™ ENERGY MONITORING
Track your body’s energy levels so you can find the best times for activity and rest(2).
IMPROVED SLEEP MONITORING AND SLEEP SCORE
Understand how your body is recovering — and get ready for training — with an improved sleep monitoring feature. After waking up, you’ll receive a sleep score, as well as breakdown of your sleep stages, Pulse Ox(3) and respiration, alongside detailed insights for improved sleep quality.
PULSE OX SENSOR
This wrist-based Pulse Ox sensor(3) monitors blood oxygen saturation levels to support advanced sleep monitoring and altitude acclimation.
WOMEN’S HEALTH TRACKING
Use the Garmin Connect app to track your menstrual cycle or pregnancy. Log symptoms, get exercise and nutrition education, and more. Even see and log details on your wrist with the Women’s Health Tracking app.
INTENSITY MINUTES
Garmin's intensity minutes feature tells you when during the day you earned them and during what activity.
STRESS TRACKING
Find out if you’re having a calm, balanced or stressful day. Relax reminders will even prompt you to do a short breathing activity when the watch detects that you’re feeling stressed.
HEALTH SNAPSHOT™ FEATURE
Log a 2-minute session to record key stats, including heart rate(2), heart rate variability, Pulse Ox(3), respiration and stress. Then generate a report with those stats to share via the Garmin Connect app on your compatible smartphone.

MULTI-BAND GNSS SUPPORT
Access multiple global navigation satellite systems, and get access to multiple frequencies sent by navigation satellites for improved accuracy in areas where GNSS signals are reflected, weak or typically don't penetrate — giving you superior accuracy for how far and how fast you’ve run — even in challenging environments.
GARMIN PAY CONTACTLESS PAYMENTS
Breeze through checkout lines with Garmin Pay contactless payments(1) through participating providers.
SMART NOTIFICATIONS
Receive emails, texts and alerts right on your watch when paired with your Apple® or Android™ smartphone. You can even respond to texts if you have an Android phone.
SAFETY AND TRACKING FEATURES
If you feel unsafe or if your watch senses that an incident occurred, the Assistance and incident detection features(4) send your location to emergency contacts. Incident detection is enabled by default for select activity profiles only.
LIVETRACK FEATURE
Use LiveTrack to let friends and family follow your real-time location(4) and even view your entire preplanned course. Rest assured that your loved ones know exactly where you’re running.
GARMIN CONNECT APP
See your health and fitness information, connect and compete with friends, sign up for challenges to earn badges and more — all in one free, zero-subscription app.
CONNECT IQ™ STORE
Download custom watch faces, add data fields, and get apps and widgets from the Connect IQ Store app downloaded on your compatible smartphone.

1 - View current supported country, payment network and issuing bank information at garmin.com/en-US/garminpay/banks/
2 - Activity tracking accuracy
3 - This is not a medical device and is not intended for use in the diagnosis or monitoring of any medical condition; see Garmin.com/ataccuracy. Pulse Ox not available in all countries.
4 - When paired with your compatible smartphone. For safety and tracking feature requirements and limitations, see Garmin.com/safety.