WatchFitTool
Garmin Forerunner® 45S — case dimensions and design

Garmin · 2019

Forerunner® 45SSize, Dimensions & Wrist Fit

Case Width

39.5mm

Thickness

11.4mm

Diameter

39.5mm

Weight

32g

The Garmin Forerunner® 45S sits best on flat wrist widths of about 42–56mm (≈ 11.2–15.0cm wrist circumference). Adjust the slider below to check your wrist.

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Does the Forerunner® 45S fit your wrist?

Drag the slider to your wrist width and see the Forerunner® 45S overlaid at true scale. Lug-to-lug — not case diameter — decides whether a watch overhangs your wrist.

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

mm
40.0mm (small)85.0mm (large)
How to Measure
1

Lay arm flat, palm up.

2

Measure the flat width across top of wrist.

Wrist Width Measurement Guide →
Garmin Forerunner® 45S (010-02156-00)
Case: 39.5mmL2L: 39.5mmThick: 11.4mm
Edge Clearance
+7.75mm
Check offer on Amazon
Balanced Fit7.75mm clearance. Comfortable everyday wear with room to spare.

Compare the Forerunner® 45S with…

vs Garmin Instinct® E – 40 mmvs Garmin Instinct® 2S - Camo Editionvs Garmin Instinct® 2S Solarvs Garmin Instinct® 2S - Standard Edition

Garmin Forerunner® 45S Full Specifications

Overview1
FamilyGarmin
General8
Battery life
Smartwatch Mode: Up to 7 days GPS mode: Up to 13 hours
Display Size1.04" (26.3 mm) diameter
Color displayYes
Lens Materialchemically strengthened glass
Memory/History80 hours of activity data
Strap materialsilicone
Charging methodGarmin proprietary plug charger
Display resolution208 x 208 pixels
Sensors5
GPSYes
GLONASSYes
GalileoYes
AccelerometerYes
Garmin Elevate™ wrist heart rate monitorYes
Product Info5
Main SKU010-02156-00
Product ID682416
Product NameForerunner® 45S
Release Date4/30/2019
Product VariationWhite
Clock Features6
TimerYes
StopwatchYes
Time/dateYes
Alarm clockYes
GPS Time SyncYes
Automatic daylight saving timeYes
Cycling Features2
Speed and cadence sensor support (w/sensor)Yes
Alerts (triggers alarm when you reach goals including time, distance, heart rate or calories)Yes
Running Features4
Run workoutsYes
Foot pod capableYes
GPS-based distance, time and paceYes
Cadence (provides real-time number of steps per minute)Yes
What You'll Love3
Display type
Sunlight-visible, transflective memory-in-pixel (MIP)
Water rating5 ATM
Battery life (smartwatch mode)Up to 7 days
Activity Profiles5
GymCardio, Elliptical Training, Stair Stepping
CyclingBiking, Indoor Biking
WellnessYoga
Indoor runningTreadmill Running, Indoor Track Running
Outdoor runningRunning
Daily Smart Features10
CalendarYes
ConnectivityYes
Find My PhoneYes
Find My WatchYes
Weather forecastsYes
Smart NotificationsYes
Smartphone compatibilityiPhone®, Android™
Controls smartphone musicYes
Pairs with Garmin Connect™ MobileYes
Connect IQ™ (downloadable watch faces, data fields and apps)yes (watch faces only)
Activity Tracking Features8
TrueUp™Yes
Move IQ™Yes
Step counterYes
Calories burnedYes
Distance traveledYes
Intensity minutesYes
Move alerts (displays on device after a period of inactivity)Yes
Auto goal (learns your activity level and assigns a daily step goal)Yes
Health & Wellness Monitoring8
Sleepyes (advanced)
Fitness ageyes (in app)
All-day stressYes
Resting heart rateYes
Abnormal heart rate alertsyes (high and low)
Relaxation breathing timerYes
Body Battery™ energy monitorYes
Wrist-based heart rate (constant, every second)Yes
Safety and Tracking Features3
Assistanceyes (smartphone required)
Live Event SharingAndroid™ Only
Incident Detection during select activitiesyes (smartphone required)
Training, Planning and Analysis Features18
HR zonesYes
HR alertsYes
Manual lapYes
HR caloriesYes
Voice alertsYes
Physio TrueUpYes
VO2 Max (Run)Yes
Advanced workoutsYes
Interval trainingYes
GPS speed and distanceYes
Customizable data pagesYes
Touch and/or button lockYes
Activity history on watchYes
Downloadable training plansYes
Customizable activity profilesYes
Auto Pause® automatic timer haltYes
Auto Lap® interval tracking featureYes
HR broadcast (broadcasts HR data over ANT+® to paired devices)Yes

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Forerunner® 45S — Frequently Asked Questions

What size is the Garmin Forerunner® 45S?

The Garmin Forerunner® 45S has a 39.5mm case and is 11.4mm thick.

Will the Garmin Forerunner® 45S fit my wrist?

The Garmin Forerunner® 45S looks balanced on flat wrist widths of roughly 42–56mm (about 11.2–15.0cm circumference). Use the interactive fit tool above to check against your own wrist.

How much does the Garmin Forerunner® 45S weigh?

The Garmin Forerunner® 45S weighs 32g (case only; straps add weight).

What is the best way to compare the Garmin Forerunner® 45S with other watches?

Use our side-by-side comparison tool to see the Garmin Forerunner® 45S next to any other watch — case size, thickness, lug-to-lug and full specs, scaled to real proportions.

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