Garmin Forerunner 45

Works with: iPhone and Android
Display: MIP, 1.04 in
Case sizes: 42 mm
Battery: 7 days
GPS battery: 13 hours
Water resistance: 5 ATM
Weight: 36 g

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Garmin Forerunner 45 at a glance

Battery

About a week

Up to 7 days in smartwatch mode. 13 hours with GPS.
GPS

Built-in GPS

No maps. Runs and rides without your phone.
Display

MIP, 1.04 in

1.04 in.
Health

Heart rate and activity

Heart rate, steps and sleep.
Phone & smart

iPhone and Android

Notifications from your phone.
Build

5 ATM water rating

36 g.

Garmin Forerunner 45 full specifications

Overview

Brand	Garmin
Model	Forerunner 45
Series	Forerunner

Platform & apps

Works with iPhone and Android phones, running Garmin.

No third-party app store: what it ships with is what you get.

Operating system	Garmin
Works with	iPhone and Android
App store	No

Display

A memory-in-pixel screen: always on, easy to read in sunlight and very light on the battery.

1.04 in.

Display type	MIP
Screen size	1.04 in
Resolution	208 x 208
Colour display	Yes

Design & durability

A 42 mm case weighing 36 g.

Rated 5 ATM: fine for swimming laps and showers.

Case sizes	42 mm
Dimensions	42 x 42 x 11.4 mm
Thickness	11.4 mm
Weight (case)	36 g
Lens	chemically strengthened glass
Band material	silicone
Fits wrists	129-197 mm
Water resistance	5 ATM

Battery

About a week: up to 7 days in smartwatch mode.

With GPS on, up to 13 hours. Real battery life depends on screen brightness, notifications and workouts.

Battery (smartwatch mode)	7 days
Battery (GPS)	13 hours
All battery modes	Smartwatch: 7 days; GPS: 13 hours
Charging	proprietary-plug

GPS & navigation

Built-in GPS, so you can record runs and rides without your phone.

GPS	Built-in
Satellite systems	GPS, GLONASS, Galileo

Health & sensors

Sensors	optical HR, accelerometer
Heart-rate sensor	Garmin Elevate
Heart-rate tracking	24/7
High/low heart-rate alerts	Yes
Stress tracking	Yes
Energy score	Body Battery

Safety

Has an emergency SOS feature.

SOS works through your paired phone. Live tracking lets friends follow your workouts.

Emergency SOS	Via phone
Incident detection	Yes
Live tracking	Yes

Training

Auto activity detection	Yes
Training metrics	VO2 max
Heart-rate broadcast	Yes
External sensors	ANT+, foot pod, speed/cadence

Smart features

Notifications	Yes
Find my phone	Yes

Specs compiled from Garmin's product pages and datasheets. Manufacturers revise hardware between versions, so check the version on the box. Spotted an error? Tell us.