Fitbit Charge 3 Fitness Tracker - Black Know yourself on a whole new level Fitbit Charge 3 reveals insights about your body, your fitness and everything in between - because the better you know yourself, the better you can be. 24/7 Heart Rate Charge 3 uses our most advanced heart rate sensors and algorithms to uncover meaningful insights on your heart. All Day Calorie Burn Know how many calories youre really burning and use what you learn to reach your goals. Real-Time Heart Rate Zones See when youre in Fat Burn, Cardio or Peak zones to make the most of every workout. Auto Sleep Tracking See how long youre in light, deep and REM sleep and get personalised insights to learn how to get better rest. Female Health Tracking Use Fitbit Charge 3 with the Fitbit app to track periods, record symptoms and estimate ovulation and fertility windows. Fitbit App Dashboard Set goals, find inspiration, connect with friends and get a snapshot of your health and fitness all in one place. Get guidance to make moves on your goals The more you wear Charge 3, the more you learn about yourself and your workouts so you can start making changes that matter. Get your favourite smart features, right on your wrist This advanced health and fitness tracker is packed with smart features that are compatible with iPhone, Android and Windows phones. Windows compatibility coming soon.