Garmin Forerunner 245 vs Garmin Forerunner 45S

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Forerunner 245 compared with Forerunner 45S

	GarminForerunner 245	GarminForerunner 45S
Overview
Released
Released	April 2019	May 2019
Display
Case sizes
Case sizes	42 mm	39.5 mm
Panel
Panel	Memory-in-pixel	Memory-in-pixel
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	1.2-inch (30.4 mm) transflective colour memory-in-pixel display, 240 x 240 pixels; button-operated.	1.04-inch colour MIP display, 208 x 208 pixels, with five-button controls.
Screen protection
Screen protection	Corning Gorilla Glass 3.	Chemically strengthened glass.
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	Yes	No
Skin temperature
Skin temperature	No	No
Sleep apnoea alerts
Sleep apnoea alerts	No	No
High blood pressure alerts
High blood pressure alerts	No	No
Body composition
Body composition	No	No
Fall detection
Fall detection	No	No
Crash detection
Crash detection	No	No
GPS
GPS	Single-band	Single-band
Water resistance
Water resistance	50 m	50 m
Sensors
Sensors	GPS, GLONASS, Galileo, Garmin Elevate wrist heart rate, Pulse Ox, compass and accelerometer.	GPS, GLONASS, Galileo, Garmin Elevate wrist heart rate and accelerometer.
Health features
Health features	Pulse Ox, sleep stages, all-day stress and Body Battery energy monitoring.	All-day heart rate, sleep and stress tracking, plus Body Battery energy monitoring.
Fitness features
Fitness features	Garmin Coach, VO2 max, training status and load, aerobic and anaerobic training effect, recovery time and running dynamics with a compatible pod or strap; breadcrumb course guidance.	Garmin Coach, VO2 max estimate and profiles for running, cycling, treadmill, elliptical, cardio and yoga activities.
Safety features
Safety features	Incident detection and assistance require a paired smartphone; LiveTrack.	Incident detection, assistance and LiveTrack require a paired phone.
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 7 days	Up to 7 days
Mobile data option
Mobile data option	No	No
Works with
Works with	iPhone and Android	iPhone and Android
Battery life detail
Battery life detail	Up to seven days in smartwatch mode or 24 hours in GPS mode.	Up to seven days in smartwatch mode, 12 hours with GPS or 11 hours with GPS and GLONASS, according to Garmin Taiwan. Garmin US lists up to 13 hours in GPS mode.
Charging
Charging	Rechargeable lithium-ion battery.	Rechargeable battery with Garmin charging cable.
Connectivity
Connectivity	Bluetooth and ANT+; smart notifications, Connect IQ and phone music controls.	Smart notifications, phone music controls and Connect IQ watch faces. No on-watch music storage.
Storage
Storage	–	Stores up to 200 hours of activity data.
Design
Weight (lightest version)
Weight (lightest version)	38.5 g	32 g (better)
Software
Software	Garmin	Garmin
Case materials
Case materials	Fibre-reinforced polymer bezel and silicone band; 5 ATM water rating.	Silicone band and 5 ATM water rating.
Size
Size	42.3 x 42.3 x 12.2 mm; 38.5 g.	39.5 x 39.5 x 11.4 mm; 32 g.
Bands
Bands	Quick-release 20 mm band; fits wrists 127–204 mm.	Fits wrists 124–185 mm.
Colours
Colours	Black case with slate grey band.	White case and band with black display bezel.