Garmin Forerunner 255 Slate Grey

You’re making strides. Now, let’s take the next step. Get the training and recovery insights you’ll need to notch your best time yet.

READY FOR THE LONG RUN

Get an uninterrupted picture of your daily health and nightly sleep with up to 14 days of battery life in smartwatch mode and up to 30 hours in GPS mode.

AS LIGHT AS A FEATHER

With its sleek design and 49g weight, you’ll almost forget you’re wearing Forerunner 255 — 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 our 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 255 watch 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 rate¹ with our 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 rest¹.

SLEEP SCORE AND ADVANCED SLEEP MONITORING

Get a score for your sleep’s quality and insights on how you can do better. Even keep track of the different sleep stages as well as heart rate, stress, Pulse Ox² and respiration.

PULSE OX SENSOR

This wrist-based Pulse Ox sensor² 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

Our 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 rate¹, heart rate variability, Pulse Ox², 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.

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 features³ 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 location³ 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.