Monitor your heart rate with Apple Watch (2024)

You can check your heart rate any time using theHeart Rate app. Open the app, then wait for Apple Watch to measure your heart rate. You can also view your resting, walking, breathe, workout, and recovery rates throughout the day.To easily open the app,add the Heart Rate complication to your watch face.

You can alsoturn on heart rate notifications, so you know if your heart rate remains above or below a chosen beats per minute (BPM), orto occasionally check for an irregular heart rhythm.

Irregular rhythm notifications are available onlywith watchOS 5.1.2 or later. To enableirregular rhythm notifications, the notifications must be available in your country or region.Learn where irregular rhythm notifications are available.

When you use the Workoutapp, Apple Watchmeasures your heart rate continuously during the workoutand for 3 minutes after the workout ends to determine a workout recovery rate. If you don't see your heart rate,check your settings.

This information, as well asother data it collects, helps Apple Watch estimate how many calories you’ve burned. In addition, Apple Watch measures your heart rate throughout the day when you’re still, and periodically when you’re walking (Apple Watch Series 1 or later). Since Apple Watch takes these background readings based on youractivity, the time between these measurements will vary. Apple Watch also calculates a daily resting rate and walking average by correlating background heart rate readings with accelerometer data when sufficient background readings are available.¹You cancontrol which third-party apps have access to your health data from the Health app in Sources.

The optical heart sensorin Apple Watch useswhat is known as photoplethysmography. Thistechnology, while difficult to pronounce, is based on a very simple fact: Blood is red because it reflects red light and absorbs green light. Apple Watch uses green LED lights paired with light‑sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. When your heart beats, the blood flow in your wrist — and the green lightabsorption — is greater. Between beats, it’s less. By flashing its LED lights hundreds of times persecond, Apple Watch can calculate the number of times the heart beats each minute— your heart rate. The optical heart sensorsupportsa range of 30–210 beats per minute. In addition, the optical heart sensor isdesigned to compensate for low signal levels by increasing both LED brightness and samplingrate.

The optical heartsensor can also use infrared light. This mode is what Apple Watch uses when itmeasures your heart rate in the background, and for heart rate notifications.Apple Watch uses green LED lights to measure your heart rate during workouts and Breathe sessions, and to calculate walking average and Heart Rate Variability (HRV).

Apple Watch Series 4 and later and all models ofApple WatchUltraalso have built-in electrodes in the Digital Crown and the back of Apple Watch, which can measure the electrical signals across your heart when used with the Heart Rate app or the ECG app. When you place your finger on the Digital Crown, it creates a closed circuit between your heart and both arms, capturing the electrical impulses across your chest.

To use the electrical heart sensor to measure your heart rate, open the Heart Rate app and place your finger on the Digital Crown. You will get a faster reading with higher fidelity—getting a measurement everysecond instead of every 5 seconds. You’ll see "ECG" in Heart Rate Context when looking at recorded data for Heart Rate in the Health app. You can also use the electrical heart sensor to take an ECG with the ECG app.

The ECG app is currently available only in certain countries and regions.Learn where the ECG app is available.

1. Some anomalies may appear in the displayed data, resulting in occasional heart rate measurements that are abnormally high or low.

2. ECG isn't supported on Apple Watch SE.