Forerunner® 405CX

Part Number: 010-00658-30


The Forerunner 405CX is the evolution of GPS-enabled training. This sleek sport watch tracks your distance, pace and heart rate, then wirelessly sends the data to your PC for later analysis. The 405CX features heart rate-based calorie computation and comes with a second wrist band option suitable for smaller wrists.

Watch Results

Loaded with serious training features, Forerunner 405CX continuously records your time, distance, pace, calories burned and heart rate. Each workout is stored in memory so you can review and analyze the data to see how you've improved. And advanced training features will challenge you to step up your pace — race against Forerunner's Virtual Partner® to improve your times, or set up interval workouts without having to circle the track. You even can download recorded courses to compete against previous workouts. To use the watch, simply tap the touch bezel to change screens without fumbling for a button.

Track Heart Rate

Forerunner 405CX comes with a flexible, wireless heart rate monitor to help you make the most of your training. The digital heart rate monitor continuously tracks heart beats per minute and uses your heart rate for advanced calorie computation, so you know how many calories you're burning. Train in a certain heart rate zone to improve your fitness level or compare your pace and heart rate to past performance on the same run.

Share Workouts Wirelessly

With Forerunner 405CX, you can share your locations, advanced workouts and courses wirelessly with other Forerunner 405 users. Send your favorite workout to your friends to try, or compete against someone else's recorded course. Sharing data is easy: just select "transfer" to send your information to a nearby device.

Run, Sync, Store and Share

Once you’ve logged the miles, innovative ANT+® wireless technology automatically transfers data to your computer when Forerunner is in range. No cables. No hookups. The data’s just there, ready for you to analyze, categorize and share through our online community, Garmin Connect™. You even can plan workouts on your computer and then send them to your Forerunner.

Train Year Round

Take your training inside with the versatile Forerunner 405CX and optional wireless accessories. Pair it with an optional foot pod to track your speed, distance and running cadence indoors when GPS signals are unavailable. The wireless foot pod clips onto your laces for easy removal and automatically turns on when you start moving. Or pair your Forerunner with an optional speed/cadence bike sensor to track the speed and distance of your cycling workouts.

ANT Firstbeat SiRF


Physical & Performance

Physical dimensions 1.88" x 2.78" x 0.646" (4.8 x 7.1 x 1.6 cm)
Display size, WxH 1.06" (2.7 cm) diameter
Display resolution, WxH 124 x 95 pixels
Weight 2.11 oz (60 g)
Battery rechargeable lithium-ion
Battery life 2 weeks in power save mode; 8 hours in training mode
Water rating IPX7
High-sensitivity receiver
Unit-to-unit transfer (shares data wirelessly with similar units)

Maps & Memory

Waypoints/favorites/locations 100
Routes 0
History 1000 laps

Cycling Features

Bike speed/cadence sensor Yes (optional)

Performance Features

Heart rate monitor
Foot pod Yes (optional)
Virtual Partner® (train against a digital person)
Courses (compete against previous activities)
Auto Pause® (pauses and resumes timer based on speed)
Auto Lap® (automatically starts a new lap)
Auto Scroll (cycles through data pages during workout)
Advanced workouts (create custom, goal-oriented workouts)
Pace alert (triggers alarm if you vary from preset pace) Yes (for advanced workouts only)
Time/distance alert (triggers alarm when you reach goal) Yes (for advanced workouts only)
Interval training (set up exercise and rest intervals)
Heart rate-based calorie computation
Customizable screen(s)
Shock Resistant

Garmin Connect™

Garmin Connect™ compatible (online community where you analyze, categorize and share data)
Automatic sync (automatically transfers data to your computer)



Watch functions include dual time, date and alarm.

Garmin Connect is compatible with Windows® XP or newer and Intel-based Mac running OS 10.4 or later with Safari.

In the Box

  • Forerunner 405CX
  • USB ANT Stick™
  • Heart rate monitor
  • Two additional wrist straps
  • AC charger
  • Charging clip
  • Manuals