Garmin · 2022
Forerunner® 255Size, Dimensions & Wrist Fit
The Garmin Forerunner® 255 sits best on flat wrist widths of about 48–65mm (≈ 12.8–17.4cm wrist circumference). Adjust the slider below to check your wrist.
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The Forerunner® 255 in short
The figures that decide whether this watch suits you, pulled out of the full specification sheet further down.
- Between 16 hours and 14 days per charge depending on the power mode — smartwatch at best, all-systems gnss plus multi-band at worst.
- Water rated to 5 ATM.
- 49g on the wrist. Lighter than 70% of the 46mm watches we have weights for.
- 1.3" (33 mm) diameter Sunlight-visible, transflective memory-in-pixel (MIP) display.
- Corning® Gorilla® Glass 3 case, Corning® Gorilla® Glass 3 glass.
Does the Forerunner® 255 fit your wrist?
Drag the slider to your wrist width and see the Forerunner® 255 overlaid at true scale. Lug-to-lug — not case diameter — decides whether a watch overhangs your wrist.
Happy with the fit? Check current availability for the Forerunner® 255.
Check offer2D Dimension Schematics
The Forerunner® 255 drawn to scale — from above, and in profile against the wrist.
- Garmin Forerunner® 25545.6mm · 12.9mm thick
3D preview
Garmin Forerunner® 255 on a wrist
On an arm sized to your own wrist — the view a product photo never gives you.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
How long the Forerunner® 255 lasts, by power mode
Runtime changes by a factor of 21 depending on what you leave switched on. Bars are scaled against the longest mode.
- Smartwatch14 days
- GPS-Only GNSS30 hours
- All-Systems GNSS25 hours
- All-Systems GNSS plus Multi-Band16 hours
How the Forerunner® 255 ranks on battery
Against the 268 Garmin watches in our database, ranked on each figure Garmin publishes.
- Everyday use14 days#116 of 257
- GPS tracking30 hours#92 of 233
Forerunner® 255 specifications
The figures that decide a purchase, followed by every line Garmin publishes.
- Battery life
- Smartwatch mode: Up to 14 days GPS-Only GNSS mode: Up to 30 hours All-Systems GNSS mode: Up to 25 hours All-Systems GNSS mode plus Multi-Band: Up to 16 hours See Details
- Display
- 1.3" (33 mm) diameter
- Resolution
- 260 x 260 pixels
- Water rating
- 5 ATM
- Bezel
- fiber-reinforced polymer
- Glass
- Corning® Gorilla® Glass 3
- Strap
- silicone
- Storage
- 4 GB
- Charging
- Garmin proprietary plug charger
Full specification sheet
230 published lines across 18 groups, unedited
Overview
- Family
- Garmin
General
- Battery life
- Smartwatch mode: Up to 14 days GPS-Only GNSS mode: Up to 30 hours All-Systems GNSS mode: Up to 25 hours All-Systems GNSS mode plus Multi-Band: Up to 16 hours See Details
- Battery type
- Lithium ion
- Display Size
- 1.3" (33 mm) diameter
- Color display
- Lens Material
- Corning® Gorilla® Glass 3
- Bezel Material
- fiber-reinforced polymer
- Memory/History
- 4 GB
- Strap material
- silicone
- Charging method
- Garmin proprietary plug charger
- Large font option
- Display resolution
- 260 x 260 pixels
- Quick Release bands
- yes (22 mm, Industry standard)
Sensors
- GPS
- QZSS
- BeiDou
- Compass
- GLONASS
- Galileo
- Gyroscope
- Thermometer
- Accelerometer
- SatIQ™ Technology
- Barometric altimeter
- Pulse Ox Blood Oxygen Saturation Monitor
- Garmin Elevate™ wrist heart rate monitor
Product Info
- Main SKU
- 010-02641-01
- Product ID
- 780139
- Product Name
- Forerunner® 255
- Release Date
- 6/1/2022
- Product Variation
- Tidal Blue
Clock Features
- Timer
- Stopwatch
- Time/date
- Alarm clock
- GPS Time Sync
- Sunrise/sunset times
- Automatic daylight saving time
Cycling Features
- Courses
- Race an activity
- Power meter compatible
- Compatible with Varia™ lights
- Speed and cadence sensor support (w/sensor)
- Bike lap and lap maximum power (with power sensor)
- Compatible with Varia™ radar (rear-facing radar)
- Compatible with Vector™ and Rally™ (power meters)
- Compatible with Varia Vision™ (head-mounted display)
- Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories)
Running Features
- Run workouts
- Running power
- Race predictor
- Foot pod capable
- Running dynamics
- Lactate threshold
- Grade-adjusted pace
- Trail run auto climb
- Performance condition
- Run/Walk/Stand detection
- Stride length (real time)
- PacePro™ Pacing Strategies
- Vertical oscillation and ratio
- Ground contact time and balance
- GPS-based distance, time and pace
- Course- and weather-specific race predictor
- Cadence (provides real-time number of steps per minute)
What You'll Love
- Display type
- Sunlight-visible, transflective memory-in-pixel (MIP)
- Water rating
- 5 ATM
- Garmin Pay™
- Multi-band GPS
- Training status
- yes (improved)
- Pulse Ox blood oxygen
- yes (spot-check, and optional all-day acclimation and in sleep)
- Sleep score and insights
- Battery life (smartwatch mode)
- Up to 14 days
Activity Profiles
- Gym
- Strength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing, Jump Roping
- Swim
- Pool Swimming, Open Water Swimming
- Cycling
- Biking, Mountain Biking, eBiking, eMountain Biking, Indoor Biking
- Wellness
- Walking, Pilates, Yoga, Indoor Walking
- Multisport
- Triathlon
- In the ring
- Boxing, Mixed Martial Arts
- Team sports
- Basketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball
- On the Water
- Stand Up Paddleboarding, Rowing
- Racket sports
- Tennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball
- Snow & winter
- Skiing, Snowboarding, XC Classic Skiing
- Indoor running
- Treadmill Running, Indoor Track Running, Virtual Running
- Outdoor running
- Running, Outdoor Track Running, Trail Running, Ultra Running
- Outdoor recreation
- Hiking, Bouldering, Archery
- Other activity profiles
- Inline skating
Swimming Features
- Pool swim workouts
- Critical swim speed
- Time and distance alerts
- Auto rest (pool swim only)
- Drill logging (pool swim only)
- Pacing alerts (pool swim only)
- Countdown start (pool swim only)
- Underwater wrist-based heart rate
- "Repeat on" rest timer (pool swim only)
- Basic rest timer (up from 0) (pool swim only)
- Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only)
- Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories)
- Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories)
- 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, HRM-Pro Plus or HRM 600)
Outdoor Recreation
- Up Ahead
- Auto rest
- TracBack®
- Back to start
- UltraTrac mode
- Vertical speed
- Elevation profile
- Projected waypoint
- Total ascent/descent
- Future elevation plot
- Distance to destination
- Sun and moon information
- Point-to-point navigation
- Bread crumb trail in real time
- Barometric trend indicator with Storm Alert
Daily Smart Features
- Stocks
- yes (optional Connect IQ app)
- Calendar
- Passcode
- Connectivity
- Bluetooth®, ANT+®
- Garmin Share
- Find My Phone
- Find My Watch
- VIRB® Remote
- Morning report
- Weather forecasts
- Smart Notifications
- Smart trainer control
- Smartphone compatibility
- iPhone® and Android™
- Controls smartphone music
- On-device Connect IQ™ Store
- Find My Phone during GPS activity
- Pairs with Garmin Connect™ Mobile
- Compatible with Garmin Messenger app
- Battery saver (customizable low power watch)
- Realtime settings sync with Garmin Connect™ mobile
- View images from notifications on watch (Android™ only)
- Text response/reject phone call with text (Android™ only)
- Connect IQ™ (downloadable watch faces, data fields and apps)
Activity Tracking Features
- TrueUp™
- Move IQ™
- Step counter
- Floors climbed
- Calories burned
- Distance traveled
- Intensity minutes
- Automatic rep counting
- Garmin Connect™ Challenges app
- yes (optional Connect IQ app)
- Auto goal (learns your activity level and assigns a daily step goal)
Workout and Training Plans
- HIIT workouts
- Yoga workouts
- Pilates workouts
- Strength workouts
- Garmin Cycling Coach
- Garmin Running Coach
- Garmin Coach - Strength
- Garmin Running Coach Experts
- On-screen workout animations
- On-screen workout muscle maps
- Daily Suggested Workout - Cycling
- Daily Suggested Workout - Running
- Garmin Coach - Prebuilt Cycling Plans
Health & Wellness Monitoring
- Sleep
- yes (advanced)
- Hydration
- yes (in Garmin Connect™ and optional Connect IQ™ widget)
- Fitness age
- Sleep coach
- Nap detection
- All-day stress
- Women's health
- yes (in Garmin Connect™ and optional Connect IQ™ widget)
- Health snapshot
- Jet lag adviser
- Respiration rate
- Resting heart rate
- Breathing variations
- Relaxation reminders
- Abnormal heart rate alerts
- yes (high and low)
- Relaxation breathing timer
- Body Battery™ energy monitor
- Wrist-based heart rate (constant, every second)
Safety and Tracking Features
- Assistance
- Live Event Sharing
- Android™ Only
- Incident Detection during select activities
- Incident detection alert on phone for wearables
Kid Activity Tracking Features
- Toe-to-Toe™ Challenges app
- yes (optional Connect IQ Toe-to-Toe™ Challenges app)
Training, Planning and Analysis Features
- % HRR
- % HR max
- HR zones
- HR alerts
- HRV status
- Load ratio
- Manual lap
- Rest timer
- Auto max HR
- Auto scroll
- Finish time
- HR calories
- Voice alerts
- Custom alerts
- Physio TrueUp
- Recovery time
- Training load
- VO2 Max (Run)
- Course guidance
- Training effect
- Virtual Partner
- Race an Activity
- Advanced workouts
- Interval training
- Race glance/widget
- Training load focus
- VO2 Max (Trail Run)
- GPS speed and distance
- Improved recovery time
- Configurable lap alerts
- Customizable data pages
- Unified training status
- Touch and/or button lock
- Activity history on watch
- Multisport auto transition
- Downloadable training plans
- Training effect (anaerobic)
- Manual multisport activities
- HRM running pace and distance
- Customizable activity profiles
- Auto Pause® automatic timer halt
- Respiration rate (during exercise)
- yes (with compatible accessory)
- Auto Lap® interval tracking feature
- Primary benefit (Training Effect labels)
- HR broadcast (broadcasts HR data over ANT+® to paired devices)
- Improved interval (includes open repeats, intervals data page, rest screen and auto detection)
Alternatives to the Forerunner® 255
Watches that cover a similar amount of wrist, with the measurements that separate them.
Garmin
Forerunner® 255 Music
- Width
- 45.6mm
- Thick
- 12.9mm
- Weight
- 49g
Garmin
Descent™ G2
- Width
- 45.5mm
- Thick
- 15.2mm
- Weight
- 65g
Garmin
Descent™ G1 Solar - Ocean Edition
- Width
- 45.5mm
- Thick
- 15.2mm
- Weight
- 61g
Garmin
Descent™ G1 Solar
- Width
- 45.5mm
- Thick
- 15.2mm
- Weight
- 66g
Garmin
Descent™ G1
- Width
- 45.5mm
- Thick
- 15.2mm
- Weight
- 61g
Garmin
Venu 2
- Width
- 45.4mm
- Thick
- 12.2mm
- Weight
- 49g
Forerunner® 255 — Frequently Asked Questions
Will the Garmin Forerunner® 255 fit my wrist?
The Garmin Forerunner® 255 looks balanced on flat wrist widths of roughly 48–65mm (about 12.8–17.4cm circumference). Drag the slider above to check it against your own measurement.
How long does the Garmin Forerunner® 255 battery last?
Between 16 hours and 14 days per charge, depending on the power mode. Garmin rates Smartwatch at 14 days and All-Systems GNSS plus Multi-Band at 16 hours; the chart above lists all 4 modes.
How does the Garmin Forerunner® 255 battery compare with other Garmin watches?
At 14 days in everyday use it ranks #116 of the 257 Garmin watches in our database — the top 45% of the range. The full ranking, including GPS and power-saving figures, is on our Garmin battery life comparison.
Is the Garmin Forerunner® 255 thick for a 46mm watch?
At 12.9mm, middle of the pack for thickness at this width. Thickness, not case width, is what decides whether a watch catches on a shirt cuff.
What other watches are the same size as the Garmin Forerunner® 255?
Honor Watch 5 Pro - Bluetooth, Huawei Watch GT 6 - 46mm, Samsung Galaxy Watch8 LTE Classic, Omega Seamaster Planet Ocean 600M Co-Axial Worldtimer 45.5 Master Chronometer GMT Ceramic / Black - Grey / Rubber all sit within half a millimetre of the Garmin Forerunner® 255's 45.6mm case, so they cover the same amount of wrist.
