Garmin Forerunner 405CX vs Garmin Forerunner 70

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

Only show differences

Better figure, where one is clearly better

Share comparison

Forerunner 405CX compared with Forerunner 70

	GarminForerunner 405CX	GarminForerunner 70
Overview
Released
Released	2009	May 2026
Display
Case sizes
Case sizes	47.75 mm	42.6 mm
Panel
Panel	–	OLED
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	Backlit monochrome screen, 27 mm diagonal and 124 × 95 pixels; touch-sensitive bezel and two buttons. Panel technology is unpublished in the maker's specification.	1.2-inch (30.4 mm diameter) colour AMOLED touchscreen, 390 x 390 pixels; optional always-on display and large-font setting; five physical buttons
Screen protection
Screen protection	–	Chemically strengthened glass
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	No	Yes
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
Sensors
Sensors	High-sensitivity GPS receiver with HotFix; ANT+ heart-rate chest strap, optional foot pod and cycling speed/cadence sensor. No optical wrist sensor.	Garmin Elevate wrist heart rate; Pulse Ox; accelerometer; ambient light sensor; no built-in barometric altimeter or body-temperature sensor
Health features
Health features	–	Continuous heart rate with high/low alerts; HRV status; Body Battery; stress and respiration; advanced sleep, sleep coach, breathing variations and nap detection; smart wake alarm; Health Snapshot; lifestyle logging; Health Status; women's health tracking via Garmin Connect; no ECG app
Fitness features
Fitness features	Heart-rate-based calorie calculation developed with Firstbeat; custom and interval workouts, courses, Virtual Partner, Auto Lap, Auto Pause, Auto Scroll and configurable training screens.	More than 80 sports apps; training readiness, status, load, load focus and recovery time; Garmin running, cycling and strength coaching; daily suggested running workouts including run/walk; quick workouts; wrist-based running dynamics and running power; PacePro; VO2 max and race predictions; breadcrumb course navigation, back-to-start and TracBack; pool swimming; no open-water swim or triathlon mode; no full offline maps
Safety features
Safety features	Up to 100 stored locations and navigation to a saved location; no base maps.	Incident detection during selected activities, assistance and LiveTrack require a paired compatible smartphone; live event sharing is Android-only; screen flashlight, not a separate LED torch
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 8 hours	Up to 13 days
In low-power mode
In low-power mode	Up to 14 days	Up to 28 days
Mobile data option
Mobile data option	No	No
Works with
Works with	No phone pairing	iPhone and Android
Battery life detail
Battery life detail	Rechargeable 300 mAh lithium-ion battery; up to eight hours with GPS or two weeks in power-save mode, according to the English owner's manual. Garmin Slovakia instead quotes nine GPS hours.	Smartwatch up to 13 days, or 5 days with display always on; battery saver smartwatch up to 28 days; GPS-only GNSS up to 23 hours; all-systems GNSS up to 16 hours; actual life depends on enabled features and usage
Charging
Charging	USB contact charging clip and AC adapter.	Garmin proprietary plug charging/data cable; rechargeable built-in lithium-ion battery; USB charging temperature 0–45 °C
Connectivity
Connectivity	ANT+ computer transfers through a USB ANT stick; Garmin Connect and Garmin Training Center. No direct phone pairing.	Bluetooth and ANT+; GPS, GLONASS and Galileo; no multi-band GNSS; Android-only text responses and notification images; Connect IQ apps/watch faces/data fields; Garmin Share; controls smartphone music without offline playback; no Garmin Pay, speaker/microphone calls or cellular connection
Storage
Storage	Up to 1,000 laps, 100 locations and approximately twenty hours of track points at one point every four seconds.	512 MB memory/history; not storage for offline music playback
Design
Weight (lightest version)
Weight (lightest version)	60 g	40 g (better)
Software
Software	Garmin	Garmin
Case materials
Case materials	IPX7 immersion protection, one metre for thirty minutes; the manual says the watch is not intended for swimming.	Fibre-reinforced polymer bezel; silicone band; chemically strengthened glass; 5 ATM water rating; operating/storage temperature –20–60 °C
Size
Size	47.75 × 70.5 × 16.4 mm and 60 g, according to the English manual; Garmin Slovakia rounds this to 48 × 71 × 16 mm. Width is used as the case size.	42.6 x 42.6 x 11.9 mm; Garmin lists 40 g without a separate body-only weight
Bands
Bands	Standard wrist strap and two additional form-fitting fabric straps for smaller or larger wrists.	Standard 20 mm quick-release silicone band; fits 126–203 mm wrists
Colours
Colours	Deep blue.	UK Black, Whitestone, Citron and Cool Lavender; global range additionally offers Tidal Blue and Soft Pink
In the box
In the box	Watch, heart-rate chest strap, USB ANT stick, AC adapter, USB charging clip, additional wrist straps and documentation.	Forerunner 70; charging cable; documentation