Garmin Forerunner 45 vs Garmin Forerunner 570

Every spec side by side, from each maker's published figures.

Better figure, where one is clearly better

Forerunner 45 compared with Forerunner 570
GarminForerunner 45GarminForerunner 570
Overview
ReleasedMay 2019May 2025
Display
Case sizes42 mm42 mm or 47 mm
PanelMemory-in-pixelOLED
Always-on displayYesYes
Display detail1.04-inch (26.3 mm) sunlight-readable colour MIP display, 208 x 208 pixels, with button controls.42 mm model has a 1.2″ (30.4 mm) AMOLED touchscreen, 390 x 390 pixels; 47 mm has a 1.4″ (35.3 mm) AMOLED touchscreen, 454 x 454 pixels; five buttons; optional always-on mode
Screen protectionChemically strengthened glass.Corning Gorilla Glass 3
Health and fitness
ECGNoNo
Blood oxygenNoYes
Skin temperatureNoYes
Sleep apnoea alertsNoNo
High blood pressure alertsNoNo
Body compositionNoNo
Fall detectionNoNo
Crash detectionNoNo
GPSSingle-bandDual-band (L1 and L5)
Water resistance50 m50 m
SensorsGPS, GLONASS, Galileo, Garmin Elevate wrist heart rate and accelerometer.Garmin Elevate wrist heart rate monitor; Pulse Ox blood oxygen monitor; barometric altimeter; compass; gyroscope; accelerometer; thermometer; ambient light sensor
Health featuresAll-day heart rate, stress and sleep tracking, plus Body Battery energy monitoring.Skin temperature; high and low heart rate alerts; HRV status; Body Battery; all-day stress; sleep score, sleep coach, sleep alignment and nap detection; breathing variations; Health Snapshot; women's health tracking with past ovulation estimates; jet lag adviser
Fitness featuresGarmin Coach, VO2 max estimate, running and cycling profiles, indoor track, treadmill, elliptical, cardio and yoga activities.Training readiness and training status; training load, load ratio and load focus; training effect, VO2 max and recovery time; wrist-based running power and dynamics; PacePro; race predictor and projected race time; Garmin Coach and Garmin Triathlon Coach plans; daily suggested workouts; multisport workouts; heat and altitude acclimation; course navigation, TracBack and Up Ahead; triathlon and open-water swimming
Safety featuresIncident detection, assistance and LiveTrack require a paired phone.Incident detection during select activities; assistance; LiveTrack; live event sharing (Android only); these features require a paired phone
Battery and connections
Battery life (maker's claim)Up to 7 daysUp to 11 days
Mobile data optionNoNo
Works withiPhone and AndroidiPhone and Android
Storage–8 GB
Battery life detailUp to seven days in smartwatch mode or 13 hours in GPS mode.Smartwatch mode up to 10 days (42 mm) or 11 days (47 mm); GPS only up to 18 hours for either size; SatIQ (AutoSelect) up to 14 or 16 hours; All-Systems + Multi-Band up to 13 or 14 hours; with music, GPS only up to nine hours and the other two modes up to eight hours for either size
ChargingRechargeable battery with Garmin charging cable.Garmin charging cable with proprietary plug
ConnectivityBluetooth and ANT+; smart notifications, phone music controls and Connect IQ watch faces. No on-watch music storage.Bluetooth, ANT+ and Wi-Fi; multi-band GPS with GPS, GLONASS, Galileo, QZSS, BeiDou and SatIQ; Garmin Pay; music storage; speaker and microphone for calls and the phone's voice assistant with a paired phone; voice commands; Garmin Share; Connect IQ
Design
Weight (lightest version)36 g (better)42 g
SoftwareGarminGarmin
Case materialsSilicone band and 5 ATM water rating.Aluminium bezel; silicone band; 5 ATM water rating
Size42 x 42 x 11.4 mm; 36 g.42 mm model is 42.4 x 42.4 x 12.9 mm and 42 g; 47 mm model is 47 x 47 x 12.9 mm and 50 g; Garmin does not publish case-only weights
BandsFits wrists 129–197 mm.Quick-release 20 mm bands for the 42 mm model, fitting 115–178 mm wrists; quick-release 22 mm bands for the 47 mm model, fitting 135–205 mm wrists
In the box–Forerunner 570, charging cable, documentation
ColoursLava red band with black case.–

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