Forerunner® 645

Part Number 010-01863-81

ONLINE STORE

Feature
Specs
In The Box
Update
Accessories
Compatible Devices

GPS Running Watch with Contactless Payments and Wrist-based Heart Rate

Provides advanced running dynamics², including ground contact time balance, stride length, vertical ratio and more
Uses wrist-based heart rate³ to offer performance monitoring features, including evaluating your current training status
Connected features4 include smart notifications, automatic uploads to Garmin Connect™ and the ability for others to track your runs with the LiveTrack feature
Customize with free watch faces, apps and more from our Connect IQ™ store
Battery life5: up to 7 days in smartwatch mode; 14 hours in GPS mode

Running is more than just exercise — it’s a performance. And Forerunner 645 has the tools to help you put on an outstanding show every time you lace up your shoes. Featuring contactless payments that let you buy what you need while on the go — plus advanced running dynamics and performance monitoring tools — this GPS running watch is the instrument you need to refine the performance.

Tune up Your Training

We’re making it easier to get the data you need to improve your form. Let Forerunner 645 measure crucial running metrics that you can use to analyze your performance. Biomechanical measurements², such as cadence, stride length, ground contact time and balance, vertical oscillation and vertical ratio, are the key to understanding your form so you can bring your best on race day. These metrics are available with the addition of a compatible heart rate strap or the compact Running Dynamics Pod, which clips right onto your waistband. Also, take advantage of feature sets to help with cycling and even swim training. In the pool, Forerunner 645 will track your distance, pace, stroke count and more.

Monitor Your Performance

Just how effective is your current training plan? Forerunner 645 will help you monitor your training and recovery so you can better prepare for a race or training cycle. Training status is a performance monitoring tool that automatically evaluates your recent exercise history and performance indicators to let you know if you’re training productively, peaking or overreaching. The anaerobic training effect metric opens a window of insight to a critical dimension of training, telling you how your training is improving your ability to push the limits. You can even view your overall training load, which measures your exercise volume from the last 7 days and compares it to the optimal range for your fitness and recent training history.

More Ways to Customize

Check out our Connect IQ store, where you can add personality to Forerunner 645 by downloading apps, widgets, watch faces and more. It’s easy and — even better — it’s free. New apps are added every day, so you can keep tabs on when your Uber is arriving, turn on your lights at home with the SmartThings app, and even use the AccuWeather MinuteCast app to find out when the rain will start. With the Face It™ watch face app, choose any image from your photo library, make some tweaks, and set it as your watch’s face.

Stay Connected on the Run

Forerunner 645 makes it easy to run without leaving important smart features behind. Once paired with your compatible smartphone, you’ll be able to receive and even respond6 to text messages and see social media updates, emails and more right on your wrist. Find your phone, access music controls, and let friends LiveTrack your runs.

Share and Compete

Syncing your activities to Garmin Connect is for more than just storing your data. Garmin Connect is a thriving online community where people on the go can connect and compete by joining challenges, encourage each other’s successes and even share their triumphs via social media. Garmin Connect is free and available on the web or on your smartphone with the Garmin Connect™ Mobileapp.

Train Your Way

Your routine is anything but routine. Forerunner 645 lets you change things up with ease, thanks to built-in activity profiles for running (indoor/outdoor), cycling (indoor/outdoor), swimming (pool), elliptical, paddle sports, strength training and many more. Create your own custom workouts, and download for free from our Garmin Connect online fitness community. Then review your past efforts on the app, or share them with family and friends for added motivation.

Love the Look

Designed for runners, Forerunner 645 features a reliable five-button interface that lets you mark laps with a quick press. Feel free to take this watch outside in all kinds of weather. Not only is it safe for swimming and showering, its Garmin Chroma Display™ is easy to read — even in direct sunlight — and housed under chemically strengthened glass. When you want to change it up, swapping bands is fast and doesn’t require tools. And with up to 7 days of battery life in smartwatch mode and 12 hours in GPS mode, Forerunner 645 is the running partner that can keep up with you.

¹View current supported country, payment network and issuing bank information
²When used with Running Dynamics Pod or HRM-Run™ or HRM-Tri™ monitor (sold separately)
³Activity tracking accuracy
⁴When paired with a compatible smartphone
⁵Battery life may vary depending on selected performance mode and usage
⁶Responding capability available for Android™ customers only

The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by Garmin is under license. Android is a registered trademark of Google Inc.

ANT+

Dedicated Website

General
Lens Material	chemically strengthened glass
Bezel Material	stainless steel
Quick Release Bands	(20 mm, Industry standard)
Strap material	silicone
Physical size	42.5 x 42.5 x 13.5 mm Fits wrists with a circumference of 127-204 mm
Weight	42.2 g
Water rating	5 ATM
Display type	sunlight-visible, transflective memory-in-pixel (MIP)
Display size	1.2" (30.4 mm) diameter
Display resolution	240 x 240 pixels
Color display
Battery life	Smartwatch Mode: Up to 7 days GPS mode: Up to 14 hours
Memory/History	200 hours of activity data

Clock Features
Time/date
GPS Time Sync
Automatic daylight saving time
Alarm clock
Timer
Stopwatch
Sunrise/sunset times
Face It™ watch face creator

Sensors
GPS
GLONASS
Garmin Elevate™ wrist heart rate monitor
Barometric altimeter
Compass
Gyroscope
Accelerometer
Thermometer

Daily Smart Features
Connectivity	Bluetooth®, ANT+®, Wi-Fi®
Connect IQ™ (downloadable watch faces, data fields, widgets and apps)
Smart notifications
Text response/reject phone call with text (Android™ only)
Calendar
Weather
Controls smartphone music
Find My Phone
Find My Watch
VIRB® remote
Smartphone compatibility	iPhone® and Android™
Compatible with Garmin Connect™ Mobile
Garmin Pay™

Activity Tracking Features
Step counter
Move bar (displays on device after a period of inactivity; walk for a couple of minutes to reset it)
Auto goal (learns your activity level and assigns a daily step goal)
Sleep monitoring (monitors total sleep and periods of movement or restful sleep)
Calories burned
Floors climbed
Distance traveled
Intensity minutes
TrueUp™
Move IQ™
Fitness Age	(in app)

Fitness Equipment/Gym
Preloaded gym activity profiles	Strength Training, Cardio Training, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing and Yoga
Cardio workouts
Strength workouts
Automatic rep counting

Training, Planning and Analysis Features
GPS speed and distance
Customizable data pages
Customizable activity profiles
Auto Pause®
Interval training
Advanced workouts
Downloadable training plans
Auto Lap®
Manual lap
Virtual Partner
Configurable lap alerts
V02 max
Training Status (lets you see if you’re training effectively by tracking your training history and fitness level trend.)
Training Load (your total training load for the last 7 days calculated from estimated EPOC)
Training Effect (aerobic)
Training Effect (anaerobic)
Customizable alerts
Audio prompts
Finish time
Race an Activity
Course guidance
Segments (Live, Garmin)
Strava features (Beacon, live segments)
LiveTrack
Touch and/or button lock
Auto scroll
Activity history on watch

Heart Rate Features
HR zones
HR alerts
HR calories
% HR max
% HRR
Recovery time
Auto max HR
HR Broadcast (broadcasts HR data over ANT+™ to paired devices)

Running Features
Preloaded run profiles	Running, Treadmill Running, Indoor Track
GPS-based distance, time and pace
Running dynamics
Cadence (provides real-time number of steps per minute)
Performance condition (after running 6–20 minutes, compares your real-time condition to your average fitness level)
Run workouts
Race predictor
Foot pod capable

Outdoor Recreation Features
Preloaded outdoor recreation profiles	Skiing, Snowboarding, XC Skiing, Stand up Paddleboarding, Rowing
Point-to-point navigation
Bread crumb trail in real time
Back to start
TracBack®
UltraTrac mode
Elevation profile
Distance to destination
Vertical speed
Total ascent/descent
GPS coordinates

Cycling Features
Preloaded cycling profiles	Biking, Indoor Biking
Courses
Race an activity
Time/distance alerts (triggers alarm when you reach goal)
Compatible with Varia Vision™ (head-mounted display)
Compatible with Varia™ radar (rear-facing radar)
Compatible with Varia™ lights
Speed and cadence sensor support (with sensor)	(ANT+® and Bluetooth® Smart)

Swimming Features
Preloaded swim profiles	Pool Swimming
Pool swim metrics (lengths, distance, pace, stroke count/rate, calories)
Stroke type detection (freestyle, backstroke, breaststroke, butterfly)
Swim efficiency (SWOLF)
Drill logging
Pool swim workouts

Forerunner 645
Charging cable
Documentation

Forerunner® 645

Forerunner® 645

General

Clock Features

Sensors

Daily Smart Features

Activity Tracking Features

Fitness Equipment/Gym

Training, Planning and Analysis Features

Heart Rate Features

Running Features

Outdoor Recreation Features

Cycling Features

Swimming Features