WatchFitTool
Garmin Forerunner® 255S — case dimensions and design

Garmin · 2022

Forerunner® 255SSize, Dimensions & Wrist Fit

Case Width

41mm

Thickness

12.4mm

Battery

12 days

Weight

39g

The Garmin Forerunner® 255S sits best on flat wrist widths of about 4359mm (≈ 11.515.8cm wrist circumference). Adjust the slider below to check your wrist.

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The Forerunner® 255S in short

The figures that decide whether this watch suits you, pulled out of the full specification sheet further down.

  • Between 13 hours and 12 days per charge depending on the power mode — smartwatch at best, all-systems gnss plus multi-band at worst.
  • Water rated to 5 ATM.
  • 12.4mm thick. Middle of the pack for thickness at this width.
  • 1.1" (27.5mm) Diameter Sunlight-visible, transflective memory-in-pixel (MIP) display.
  • Corning® Gorilla® Glass 3 case, Corning® Gorilla® Glass 3 glass.

Does the Forerunner® 255S fit your wrist?

Drag the slider to your wrist width and see the Forerunner® 255S overlaid at true scale. Lug-to-lug — not case diameter — decides whether a watch overhangs your wrist.

Watch Fit Tool

For sports watches, Lug-to-Lug (L2L) is what matters most. Bulky is fine — overhang is not.

mm
40.0mm (small)80.0mm (large)
How to Measure
1

Lay arm flat, palm up.

2

Measure the flat width across top of wrist.

Garmin Forerunner® 255S
010-02641-02
Case: 41mmL2L: 41mmThick: 12.4mm
Edge Clearance
+7mm
Balanced Fit7mm clearance. Comfortable everyday wear with room to spare.

Happy with the fit? Check current availability for the Forerunner® 255S.

Check offer

2D Dimension Schematics

The Forerunner® 255S drawn to scale — from above, and in profile against the wrist.

Highlight
From above — true scale
From the side — how far it sits off the wrist
  • Garmin Forerunner® 255S41mm · 12.4mm thick

3D preview

Garmin Forerunner® 255S on a wrist

On an arm sized to your own wrist — the view a product photo never gives you.

Open 3D try-on

Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.

How long the Forerunner® 255S lasts, by power mode

Runtime changes by a factor of 22 depending on what you leave switched on. Bars are scaled against the longest mode.

  • Smartwatch12 days
  • GPS-only GNSS26 hours
  • All-Systems GNSS20 hours
  • All-Systems GNSS plus Multi-Band13 hours

How the Forerunner® 255S ranks on battery

Against the 214 Garmin watches in our database, ranked on each figure Garmin publishes.

  • Everyday use12 days#113 of 203
  • GPS tracking26 hours#89 of 190
See all 214 Garmin watches ranked by battery life

Forerunner® 255S specifications

The figures that decide a purchase, followed by every line Garmin publishes.

Battery life
Smartwatch mode: Up to 12 days GPS-only GNSS mode: Up to 26 hours All-Systems GNSS mode: Up to 20 hours All-Systems GNSS mode plus Multi-Band: Up to 13 hours See Details
Display
1.1" (27.5mm) Diameter
Resolution
218 x 218 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

219 published lines across 18 groups, unedited

Overview

Family
Garmin

General

Battery life
Smartwatch mode: Up to 12 days GPS-only GNSS mode: Up to 26 hours All-Systems GNSS mode: Up to 20 hours All-Systems GNSS mode plus Multi-Band: Up to 13 hours See Details
Display Size
1.1" (27.5mm) 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
218 x 218 pixels
Quick Release bands
yes (18 mm, Industry standard)

Sensors

GPS
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
010-02641-02
Product ID
780165
Product Name
Forerunner® 255S
Release Date
6/1/2022
Product Variation
Powder Gray

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
FTP (Functional Threshold Power)
yes (with compatible accessory)
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
yes (with compatible accessory)
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)
Daily suggested workouts
yes (7 days)
Sleep score and insights
Battery life (smartwatch mode)
Up to 12 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 or HRM-Pro Plus)

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
Connectivity
Bluetooth®, ANT+®
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, widgets and apps)

Gym & Fitness Equipment

HIIT workouts
Yoga workouts
Pilates workouts
Strength workouts
Automatic rep counting
On-screen workout animations
On-screen workout muscle maps

Activity Tracking Features

TrueUp™
Move IQ™
Step counter
Floors climbed
Calories burned
Distance traveled
Intensity minutes
Garmin Connect™ Challenges app
yes (optional Connect IQ app)
Auto goal (learns your activity level and assigns a daily step goal)

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
Relaxation reminders
Respiration rate (24x7)
Daily resting heart rate
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

LiveTrack
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
Auto Lap®
HRV status
Load ratio
Manual lap
Rest timer
Auto max HR
Auto scroll
Finish time
HR calories
Auto Pause®
Audio prompts
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
Configurable lap alerts
Customizable data pages
Unified training status
Touch and/or button lock
Activity history on watch
Auto multisport activities
Multisport auto transition
Downloadable training plans
Training effect (anaerobic)
Manual multisport activities
HRM running pace and distance
Customizable activity profiles
Respiration rate (during exercise)
yes (with compatible accessory)
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)

Forerunner® 255S — Frequently Asked Questions

Will the Garmin Forerunner® 255S fit my wrist?

The Garmin Forerunner® 255S looks balanced on flat wrist widths of roughly 43–59mm (about 11.5–15.8cm circumference). Drag the slider above to check it against your own measurement.

How long does the Garmin Forerunner® 255S battery last?

Between 13 hours and 12 days per charge, depending on the power mode. Garmin rates Smartwatch at 12 days and All-Systems GNSS plus Multi-Band at 13 hours; the chart above lists all 4 modes.

How does the Garmin Forerunner® 255S battery compare with other Garmin watches?

At 12 days in everyday use it ranks #113 of the 203 Garmin watches in our database — below the middle of the range. The full ranking, including GPS and power-saving figures, is on our Garmin battery life comparison.

Is the Garmin Forerunner® 255S thick for a 41mm watch?

At 12.4mm, 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® 255S?

TAG Heuer Carrera Chronograph Glass Box 41 Stainless Steel / Black, Zenith Defy Skyline Tourbillon Skeleton Rose Gold / Blue, Huawei Watch GT 6 - 41mm, Google Pixel Watch 4 - 41mm all sit within half a millimetre of the Garmin Forerunner® 255S's 41mm case, so they cover the same amount of wrist.