GARMIN Forerunner 255S Music

General
LENS MATERIAL Corning® Gorilla® Glass 3
BEZEL MATERIAL Fiber-reinforced polymer
QUICK RELEASE BANDS Yes (18 mm, Industry standard)
STRAP MATERIAL Silicone
PHYSICAL SIZE 41 x 41 x 12.4 (mm)
Fits wrists with a circumference of 110-175 mm
COLOUR DISPLAY
DISPLAY SIZE 1.1" (27.5mm) Diameter
DISPLAY RESOLUTION 218 x 218 pixels
DISPLAY TYPE Sunlight-visible, transflective memory-in-pixel (MIP)
WEIGHT 39 g
WATER RATING 5 ATM
BATTERY LIFE Smartwatch mode: Up to 12 days
GPS-only GNSS mode: Up to 26 hours
All-Systems GNSS mode with music: Up to 5.5 hours
All-Systems GNSS mode: Up to 20 hours
All-Systems GNSS mode plus Multi-Band: Up to 13 hours
See details
CHARGING METHOD Garmin proprietary plug charger
MEMORY/HISTORY 4 GB

Clock features
TIME/DATE
GPS TIME SYNC
AUTOMATIC DAYLIGHT SAVING TIME
ALARM CLOCK
TIMER
STOPWATCH
SUNRISE/SUNSET TIMES

Health monitoring
WRIST-BASED HEART RATE (CONSTANT, EVERY SECOND)
DAILY RESTING HEART RATE
ABNORMAL HEART RATE ALERTS Yes (high and low)
RESPIRATION RATE (24X7)
PULSE OX BLOOD OXYGEN SATURATION Yes (spot-check, and optional all-day acclimation and in sleep)
FITNESS AGE
BODY BATTERY™ ENERGY MONITOR
ALL-DAY STRESS
RELAXATION REMINDERS
RELAXATION BREATHING TIMER
SLEEP Yes (Advanced)
SLEEP SCORE AND INSIGHTS
HYDRATION Yes (in Garmin Connect™ and optional Connect IQ™ widget)
WOMEN'S HEALTH Yes (in Garmin Connect™ and optional Connect IQ™ widget)
HEALTH SNAPSHOT

Sensors
GPS
GLONASS
GALILEO
MULTI-FREQUENCY POSITIONING
SATIQ™ TECHNOLOGY
GARMIN ELEVATE™ WRIST HEART RATE MONITOR
BAROMETRIC ALTIMETER
COMPASS
GYROSCOPE
ACCELEROMETER
THERMOMETER
PULSE OX BLOOD OXYGEN SATURATION MONITOR

Daily smart features
BATTERY SAVER - CUSTOMISABLE LOW POWER WATCH
CONNECT IQ™ (DOWNLOADABLE WATCH FACES, DATA FIELDS, WIDGETS AND APPS)
CONNECTIVITY Bluetooth®, ANT+®
FIND MY WATCH
GARMIN PAY™
COMPATIBLE WITH GARMIN CONNECT™ MOBILE
CONTROLS SMARTPHONE MUSIC
MUSIC STORAGE
ON-DEVICE CONNECT IQ™ STORE
FIND MY PHONE
PLAYS AND CONTROLS WATCH MUSIC
REALTIME SETTINGS SYNC WITH GARMIN CONNECT™ MOBILE
CALENDAR
SMART NOTIFICATIONS
SMARTPHONE COMPATIBILITY iPhone® and Android™
WEATHER
STOCKS Yes (optional Connect IQ app)
TEXT RESPONSE/REJECT PHONE CALL WITH TEXT (ANDROID™ ONLY)
VIRB® CAMERA REMOTE

Safety and tracking features
LIVETRACK
LIVE EVENT SHARING Android™ Only
INCIDENT DETECTION DURING SELECT ACTIVITIES
INCIDENT DETECTION ALERT ON PHONE FOR WEARABLES
ASSISTANCE
Activity tracking features
STEP COUNTER
AUTO GOAL (LEARNS YOUR ACTIVITY LEVEL AND ASSIGNS A DAILY STEP GOAL)
CALORIES BURNED
FLOORS CLIMBED
DISTANCE TRAVELLED
INTENSITY MINUTES
TRUEUP™
MOVE IQ™
GARMIN CONNECT™ CHALLENGES APP Yes (optional Connect IQ app)

Fitness equipment/gym
AUTOMATIC REP COUNTING
STRENGTH WORKOUTS
HIIT WORKOUTS
YOGA WORKOUTS
PILATES WORKOUTS
ON-SCREEN WORKOUT ANIMATIONS
ON-SCREEN WORKOUT MUSCLE MAP

Training, planning and analysis features
HR ZONES
HR ALERTS
HR CALORIES
% HR MAX
% HRR
RECOVERY TIME
AUTO MAX HR
MORNING REPORT
RACE GLANCE/WIDGET
HRV STATUS
HR BROADCAST (BROADCASTS HR DATA OVER ANT+™ TO PAIRED DEVICES)
RESPIRATION RATE (DURING EXERCISE) Yes (with compatible accessory)
GPS SPEED AND DISTANCE
CUSTOMISABLE SCREEN(S)
CUSTOMISABLE ACTIVITY PROFILES
AUTO PAUSE®
INTERVAL TRAINING
IMPROVED INTERVAL (INCLUDES OPEN REPEATS, INTERVALS DATA PAGE, REST SCREEN AND AUTO DETECTION)
ADVANCED WORKOUTS
DOWNLOADABLE TRAINING PLANS
HRM RUNNING PACE AND DISTANCE
AUTO LAP®
MANUAL LAP
REST TIMER
CONFIGURABLE LAP ALERTS
VO2 MAX (RUN)
VO2 MAX (TRAIL RUN)
TRAINING STATUS Improved
TRAINING LOAD
TRAINING LOAD FOCUS
TRAINING EFFECT
TRAINING EFFECT (ANAEROBIC)
PRIMARY BENEFIT (TRAINING EFFECT LABELS)
IMPROVED RECOVERY TIME
DAILY SUGGESTED WORKOUTS Yes (7 days)
CUSTOMISABLE ALERTS
AUDIO PROMPTS
FINISH TIME
VIRTUAL PARTNER
RACE AN ACTIVITY
AUTO MULTISPORT ACTIVITIES
MULTI-SPORT
COURSE GUIDANCE
TOUCH AND/OR BUTTON LOCK
AUTO SCROLL
ACTIVITY HISTORY ON WATCH
PHYSIO TRUEUP
UNIFIED TRAINING STATUS

Running features
AVAILABLE RUN PROFILES Running, Outdoor Track Running, Treadmill Running, Indoor Track Running, Trail Running, Virtual Running, Ultra Running
GPS-BASED DISTANCE, TIME AND PACE
RUNNING DYNAMICS
VERTICAL OSCILLATION AND RATIO
GROUND CONTACT TIME AND BALANCE
STRIDE LENGTH (REAL TIME)
CADENCE (PROVIDES REAL-TIME NUMBER OF STEPS PER MINUTE)
RUNNING POWER
GRADE-ADJUSTED PACE
PERFORMANCE CONDITION
LACTATE THRESHOLD Yes (with compatible accessory)
PACEPRO™ PACING STRATEGIES
RUN WORKOUTS
TRAIL RUN AUTO CLIMB
RACE PREDICTOR
COURSE- AND WEATHER-SPECIFIC RACE PREDICTOR
FOOT POD CAPABLE
RUN/WALK/STAND DETECTION

Outdoor recreation
AVAILABLE OUTDOOR RECREATION PROFILES Hiking, Skiing, Snowboarding, XC Classic Skiing, Stand Up Paddleboarding, Rowing
POINT-TO-POINT NAVIGATION
BREAD CRUMBTRAIL IN REAL TIME
BACK TO START
TRACBACK®
ULTRATRAC MODE
UP AHEAD
ELEVATION PROFILE
DISTANCE TO DESTINATION
BAROMETRIC TREND INDICATOR WITH STORM ALERT
VERTICAL SPEED
TOTAL ASCENT/DESCENT
AUTO REST
FUTURE ELEVATION PLOT
PROJECTED WAYPOINT
SUN AND MOON INFORMATION

Cycling features
AVAILABLE CYCLING PROFILES Biking, Indoor Biking, Mountain Biking, eBiking, eMountain Biking
ALERTS (TRIGGERS ALARM WHEN YOU REACH GOALS INCLUDING TIME, DISTANCE, HEART RATE OR CALORIES)
COURSES
BIKE LAP AND LAP MAXIMUM POWER (WITH POWER SENSOR)
RACE AN ACTIVITY
FTP (FUNCTIONAL THRESHOLD POWER) Yes (with compatible accessory)
COMPATIBLE WITH VECTOR™ AND RALLY™ (POWER METERS)
POWER METER COMPATIBLE
COMPATIBLE WITH VARIA VISION™ (HEAD-MOUNTED DISPLAY)
COMPATIBLE WITH VARIA™ RADAR (REAR-FACING RADAR)
COMPATIBLE WITH VARIA™ LIGHTS
SPEED AND CADENCE SENSOR SUPPORT (W/SENSOR)

Swimming features
AVAILABLE SWIM PROFILES Pool swimming, open water swimming
OPEN-WATER SWIM METRICS (DISTANCE, PACE, STROKE COUNT/RATE, STROKE DISTANCE, SWIM EFFICIENCY (SWOLF), CALORIES)
POOL SWIM METRICS (LENGTHS, DISTANCE, PACE, STROKE COUNT, SWIM EFFICIENCY (SWOLF), CALORIES)
STROKE TYPE DETECTION (FREESTYLE, BACKSTROKE, BREASTSTROKE, BUTTERFLY) (POOL SWIM ONLY)
DRILL LOGGING (POOL SWIM ONLY)
BASIC REST TIMER (UP FROM 0) (POOL SWIM ONLY)
"REPEAT ON" REST TIMER (POOL SWIM ONLY)
AUTO REST (POOL SWIM ONLY)
TIME AND DISTANCE ALERTS
PACING ALERTS (POOL SWIM ONLY)
COUNTDOWN START
POOL SWIM WORKOUTS
CRITICAL SWIM SPEED
UNDERWATER WRIST-BASED HEART RATE
HEART RATE FROM EXTERNAL HRM (REAL-TIME DURING RESTS, INTERVAL AND SESSION STATS DURING RESTS, AND AUTOMATIC HEART RATE DOWNLOAD POST-SWIM) Yes (with HRM-Swim, HRM-Pro or HRM-Pro Plus)

Kid activity tracking features
TOE-TO-TOE™ CHALLENGES APP Yes (optional Connect IQ Toe-to-Toe™ Challenges app)

Connectivity
SMART TRAINER CONTROL