WatchFitTool

Garmin Forerunner® 165 vs Garmin Instinct® E – 40 mmSize, Specs & Wrist Fit Compared

The Garmin Forerunner® 165 wears larger than the Garmin Instinct® E – 40 mm (43mm vs 40mm case), giving it more wrist presence — and needing a wider wrist to sit cleanly.

The Garmin Forerunner® 165 is the slimmer of the two (11.6mm vs 13.6mm), so it slides under a cuff more easily.

On the wrist the Garmin Forerunner® 165 feels lighter (39g vs 41g, case only).

Specification Comparison

SpecGarminForerunner® 165GarminInstinct® E – 40 mm
Case Width43mm40mm
Thickness11.6mm13.6mm
Weight39g41g
ShapeCircularCircular
GPSYesYes
Battery LifeSmartwatch mode: Up to 11 days Battery Saver Smartwatch mode: Up to 20 days GPS-Only GNSS mode: Up to 19 hours All-Systems GNSS mode: Up to 17 hours See DetailsSmartwatch: Up to 14 days Battery Saver Watch Mode: Up to 35 days GPS: Up to 21 hours All Satellite Systems: 14 hours Max Battery GPS Mode: Up to 43 hours Expedition GPS Activity: Up to 17 days
DisplayAMOLED (optional always-on mode)Monochrome, sunlight-visible, transflective memory-in-pixel (MIP)
Released20242025

Full Specification Comparison

219 specs
SpecGarmin Forerunner® 165Garmin Instinct® E – 40 mm
Overview
FamilyGarminGarmin
General
Battery lifeSmartwatch mode: Up to 11 days Battery Saver Smartwatch mode: Up to 20 days GPS-Only GNSS mode: Up to 19 hours All-Systems GNSS mode: Up to 17 hours See DetailsSmartwatch: Up to 14 days Battery Saver Watch Mode: Up to 35 days GPS: Up to 21 hours All Satellite Systems: 14 hours Max Battery GPS Mode: Up to 43 hours Expedition GPS Activity: Up to 17 days
Battery typeLithium ionLithium ion
Display Size1.2" (30.4 mm) diametercustom, two-window design; 0.86” x 0.86” (22 x 22 mm)
Color displayYes
Lens Materialchemically strengthened glassChemically Strengthened Glass
Bezel Materialfiber-reinforced polymerfiber-reinforced polymer
Memory/History4 GB128 MB
Strap materialsiliconesilicone
Charging methodGarmin proprietary plug chargerGarmin proprietary plug charger
Large font optionYes
Display resolution390 x 390 pixels166 x 166 pixels (active area)
Quick Release bandsyes (20 mm, Industry standard)
Case materialfiber-reinforced polymer
QuickFit® watch band compatibleyes (20 mm)
Sensors
GPSYesYes
CompassYesYes
GLONASSYesYes
GalileoYesYes
ThermometerYesYes
AccelerometerYesYes
Ambient light sensorYes
Barometric altimeterYesYes
Pulse Ox Blood Oxygen Saturation MonitorYesYes
Garmin Elevate™ wrist heart rate monitorYesYes
Product Info
Main SKU010-02863-20010-02932-00
Product ID10554691314137
Product NameForerunner® 165Instinct® E – 40 mm
Release Date2/20/20241/6/2025
Product VariationBlack/Slate GrayBlack with Charcoal Band
Clock Features
TimerYesYes
StopwatchYesYes
Time/dateYesYes
Alarm clockYesYes
GPS Time SyncYesYes
Sunrise/sunset timesYesYes
Automatic daylight saving timeYesYes
Cycling Features
CoursesYesYes
Compatible with Varia™ lightsYesYes
Compatible with Varia headlight cameraYes
Speed and cadence sensor support (w/sensor)YesYes
Compatible with Varia™ radar (rear-facing radar)Yes
Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories)YesYes
Race an activityYes
Running Features
Run workoutsYesYes
Running powerYes
Race predictorYesYes
Foot pod capableYesYes
Running dynamicsYesYes
Run/Walk/Stand detectionYesYes
Stride length (real time)YesYes
PacePro™ Pacing StrategiesYes
Vertical oscillation and ratioYesYes
Ground contact time and balanceyes (but not balance)yes (but not balance)
GPS-based distance, time and paceYesYes
Course- and weather-specific race predictorYes
Cadence (provides real-time number of steps per minute)YesYes
Trail run auto climbYes
What You'll Love
TouchscreenYes
Display typeAMOLED (optional always-on mode)Monochrome, sunlight-visible, transflective memory-in-pixel (MIP)
Water rating5 ATM10 ATM
Garmin Pay™Yes
Pulse Ox blood oxygenyes (spot-check, during sleep, all day)Yes
Sleep score and insightsYesYes
Battery life (smartwatch mode)Up to 11 daysUp to 14 days
Activity Profiles
GymStrength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor ClimbingStrength, HIIT, Cardio, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing
SwimPool Swimming, Open Water SwimmingPool Swimming, Open Water Swimming
CyclingBiking, Indoor BikingBiking, Road Biking, Mountain Biking, Gravel Biking, Bike Commuting, Bike Touring, eBiking, eMountain Biking, Indoor Biking, Cyclocross, BMX
WellnessWalking, Pilates, Yoga, Indoor WalkingWalking, Pilates, Yoga
Racket sportsTennis, Pickleball, PadelTennis, Pickleball, Badminton, Squash, Table Tennis, Padel, Platform Tennis, Racquetball
Indoor runningTreadmill Running, Indoor Track Running, Virtual RunningTreadmill Running, Indoor Track Running, Virtual Running
Outdoor runningRunning, Outdoor Track Running, Trail Running, Ultra RunningRunning, Outdoor Track Running, Trail Running
Outdoor recreationHikingHiking, Climbing, Hunting, Horseback Riding, Archery
Team sportsBasketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball
On the WaterStand Up Paddleboarding, Rowing, Kayaking, Fishing, Boating, Whitewater
Snow & winterSkiing, Snowboarding, XC Classic Skiing, XC Skate Skiing, Ice Skating, Snowshoeing
Other activity profilesTactical
Swimming Features
Time and distance alertsYesYes
Auto rest (pool swim only)YesYes
Drill logging (pool swim only)YesYes
Countdown start (pool swim only)YesYes
Underwater wrist-based heart rateYesYes
"Repeat on" rest timer (pool swim only)YesYes
Basic rest timer (up from 0) (pool swim only)YesYes
Stroke type detection (freestyle, backstroke, breaststroke, butterfly) (pool swim only)YesYes
Pool swim metrics (lengths, distance, pace, stroke count, swim efficiency (SWOLF), calories)YesYes
Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, swim efficiency (SWOLF), calories)YesYes
Pool swim workoutsYes
Outdoor Recreation
Auto restYes
TracBack®YesYes
Back to startYesYes
Fish forecastyes (via Connect IQ™)
UltraTrac modeYesYes
Area calculationyes (via Connect IQ™)Yes
Elevation profileYesYes
Total ascent/descentYesYes
Future elevation plotYesYes
Distance to destinationYesYes
Sun and moon informationyes (via Connect IQ™)Yes
Point-to-point navigationYesYes
Rest Timer (Ultra Run only)Yes
Bread crumb trail in real timeYesYes
TidesYes
Sight 'N GoYes
Tide glanceYes
Vertical speedYes
GPS coordinatesYes
Reference pointYes
Projected waypointYes
Expedition GPS ActivityYes
Barometric trend indicator with Storm AlertYes
Daily Smart Features
CalendarYesYes
PasscodeYesYes
ConnectivityBluetooth®, ANT+®Bluetooth®, ANT+®
Garmin ShareYesYes
Find My PhoneYesYes
Find My WatchYesYes
Morning reportYesYes
Red shift modeYes
Weather forecastsYesYes
Smart NotificationsYesYes
Smartphone compatibilityiPhone®, Android™iPhone®, Android™
Controls smartphone musicYesYes
On-device Connect IQ™ StoreYesYes
Find My Phone during GPS activityYes
Pairs with Garmin Connect™ MobileYesYes
Compatible with Garmin Messenger appYes
Battery saver (customizable low power watch)YesYes
Realtime settings sync with Garmin Connect™ mobileYesYes
View images from notifications on watch (Android™ only)Yes
Text response/reject phone call with text (Android™ only)YesYes
Connect IQ™ (downloadable watch faces, data fields and apps)YesYes
VIRB® RemoteYes
Activity Tracking Features
TrueUp™YesYes
Move IQ™YesYes
Step counterYesYes
Floors climbedYesYes
Calories burnedYesYes
Distance traveledYesYes
Intensity minutesYesYes
Automatic rep countingYesYes
Garmin Connect™ Challenges appyes (optional Connect IQ app)yes (optional Connect IQ app)
Move alerts (displays on device after a period of inactivity)YesYes
Auto goal (learns your activity level and assigns a daily step goal)YesYes
Workout and Training Plans
HIIT workoutsYesYes
Yoga workoutsYesYes
Cardio workoutsYesYes
Pilates workoutsYesYes
Strength workoutsYesYes
Garmin Running Coachyes (no strength add-on)
Garmin Running Coach ExpertsYesYes
Garmin Coach - Prebuilt Cycling PlansYesYes
Daily Suggested Workout - Running (Pace and Heart Rate Based)YesYes
Daily Suggested Workout - Cycling (Pace and Heart Rate Based)Yes
Health & Wellness Monitoring
Sleepyes (advanced)yes (advanced)
Hydrationyes (in Garmin Connect™ and optional Connect IQ™ widget)yes (in Garmin Connect™ and optional Connect IQ™ widget)
BreathworkYesYes
Fitness ageYesYes
Nap detectionYesYes
All-day stressYesYes
Women's healthyes (in Garmin Connect™ and optional Connect IQ™ widget)yes (in Garmin Connect™ and optional Connect IQ™ widget)
Health snapshotYesYes
Respiration rateYesYes
Resting heart rateYesYes
Breathing variationsYesYes
Relaxation remindersYesYes
Abnormal heart rate alertsyes (high and low)yes (high and low)
Relaxation breathing timerYesYes
Body Battery™ energy monitorYesYes
Wrist-based heart rate (constant, every second)YesYes
Safety and Tracking Features
AssistanceYesYes
Live Event SharingAndroid™ OnlyYes
Incident Detection during select activitiesYesYes
Incident detection alert on phone for wearablesYesYes
Kid Activity Tracking Features
Toe-to-Toe™ Challenges appyes (optional Connect IQ Toe-to-Toe™ Challenges app)yes (optional Connect IQ Toe-to-Toe™ Challenges app)
Training, Planning and Analysis Features
% HRRYesYes
% HR maxYesYes
HR zonesYesYes
HR alertsYesYes
HRV statusYesYes
Manual lapYesYes
Rest timerYesYes
Auto max HRYesYes
Finish timeYesYes
HR caloriesYesYes
Voice alertsYesYes
Physio TrueUpYesYes
Recovery timeYesYes
VO2 Max (Run)YesYes
Course guidanceYesYes
Training effectYesYes
Advanced workoutsYesYes
Interval trainingYesYes
Race glance/widgetYes
VO2 Max (Trail Run)YesYes
GPS speed and distanceYesYes
Configurable lap alertsYesYes
Customizable data pagesYesYes
Touch and/or button lockYesYes
Activity history on watchYesYes
Downloadable training plansYesYes
Training effect (anaerobic)YesYes
HRM running pace and distanceYesYes
Customizable activity profilesYesYes
Auto Pause® automatic timer haltYesYes
Respiration rate (during exercise)Yoga and Breathwork onlyYoga and Breathwork only
Auto Lap® interval tracking featureYesYes
Primary benefit (Training Effect labels)YesYes
HR broadcast (broadcasts HR data over ANT+® to paired devices)YesYes
ShortcutsYes
Auto scrollYes
Custom alertsYes
Virtual PartnerYes
Workout benefitYes
Race an ActivityYes
Heat and altitude acclimationYes
Power Modes - customizable in-activity battery settingsYes
Tactical Features
XERO™ LocationsYes
Dual grid coordinatesYes

Wrist Fit

Garmin Forerunner® 165

Sits best on wrists ~4561mm wide (≈ 12.016.3cm circumference).

Garmin Instinct® E – 40 mm

Sits best on wrists ~4257mm wide (≈ 11.215.2cm circumference).

2D Dimension Schematics

Accurate scale drawings based on case dimensions. Drag to pan, Ctrl+scroll to zoom. Works for every watch regardless of photo availability.

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Product Photos

Side-by-side product images at matched scale.

Garmin Forerunner® 165 (010-02863-20)
Garmin Forerunner® 165 (010-02863-20)
43mm × 43mm
Garmin Instinct® E – 40 mm (010-02932-00)
Garmin Instinct® E – 40 mm (010-02932-00)
40mm × 40mm

Frequently Asked Questions

Is the Garmin Forerunner® 165 bigger than the Garmin Instinct® E – 40 mm?

The Garmin Forerunner® 165 is bigger — 43mm vs 40mm case width.

Which fits a smaller wrist better, the Garmin Forerunner® 165 or the Garmin Instinct® E – 40 mm?

The Garmin Forerunner® 165 suits wrists around 45–61mm wide, and the Garmin Instinct® E – 40 mm around 42–57mm. The one with the smaller lower bound is the safer pick for a small wrist.

Can I see the Garmin Forerunner® 165 and Garmin Instinct® E – 40 mm side by side at true scale?

Yes — the schematics and photos above show both watches at matched scale, and our fit tool overlays each on your wrist width.

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