The Apple Watch can’t measure your weight, but it can use and show the weight you record. You log your weight in the Health app on your iPhone (or let a smart scale do it for you), and the watch uses that number to estimate the calories you burn. To add a reading, open Health on your iPhone, tap Browse > Body Measurements > Weight > Add Data, enter your weight, and tap Add.
Below are the ways to record your weight, how to keep the number your watch uses up to date, and how to see your weight trend over time.
Why your weight matters to the Apple Watch
Your Apple Watch combines your heart rate and movement with your height, weight, age and sex to estimate Active Energy, the calories that fill your Move ring. If the weight in your Health Details is old, those calorie numbers will be off. Someone who has lost 20 pounds but never updated their weight will see higher calorie burns than they’re really getting.
That’s why it’s worth updating your weight regularly even if you don’t care about a weight chart. A weekly reading is plenty for accurate calorie estimates.
Log your weight in the Health app on iPhone
- Open the Health app on your iPhone.
- Tap Browse at the bottom of the screen.
- Tap Body Measurements, then tap Weight.
- Tap Add Data at the top right.
- Enter your weight. You can change the date and time if you’re logging an earlier reading.
- Tap Add.
On the Weight screen, scroll down and turn on Add to Favorites so your weight shows on the Health app’s Summary tab. That makes it one tap away the next time you want to log a reading.
If you’d rather use kilograms or stones, tap Weight, scroll to the bottom, tap Unit, and choose the one you want.
Update the weight your Apple Watch uses
The newest weight you log in Health is used automatically. You can also check or change it directly from the Watch app:
- Open the Watch app on your iPhone.
- Tap the My Watch tab.
- Tap Health, then Health Details.
- Tap Edit, tap Weight, and set your current weight.
- Tap Done.
On the watch itself, you can view and edit the same Health Details in the Settings app under Health on recent versions of watchOS.
Track your weight automatically with a smart scale
A Wi-Fi or Bluetooth smart scale is the easiest way to keep a weight history, because you never have to type anything. Most popular scales have an iPhone app that can write to Apple Health.
- Set up the scale with its own app on your iPhone.
- In that app, find the Apple Health or Connected Apps setting and turn on sharing.
- When the Health permission screen appears, allow the app to write Weight (and body fat percentage or BMI if the scale measures them).
- Step on the scale. The reading syncs to the scale’s app and then to Health, where your watch picks it up.
If readings stop showing up, open the scale’s app once so it can sync, and check Health > your profile picture > Apps to make sure the scale’s app still has permission to write data.
Log your weight from your wrist
Apple doesn’t include a weight-logging app on the watch, but you have two options if you want to record a reading without picking up your phone.
- A third-party app: Search the App Store for a weight tracker that lists Apple Watch support and Apple Health syncing. These apps let you dial in your weight with the Digital Crown and save it straight to Health.
- A shortcut: In the Shortcuts app on your iPhone, create a shortcut with the Log Health Sample action, set the type to Weight, and set the value to Ask Each Time. Open the shortcut’s details and turn on Show on Apple Watch. You can then run it from the Shortcuts app on the watch. If it won’t run there, keep it on your iPhone home screen instead.
See your weight trend
- Open Health and tap your Weight favorite, or go to Browse > Body Measurements > Weight.
- Tap D, W, M, 6M or Y at the top to change the time range.
- Tap Show All Data near the bottom to see every reading, where it came from, and to delete a wrong entry.
The Health app doesn’t let you set a weight goal. If you want a target and progress bar, a third-party app that reads your Health weight data is the way to go.
Other body measurements to keep current
Weight isn’t the only detail that affects your watch’s estimates. While you’re in Health Details, check these too:
- Height: Used with your weight for calorie estimates and to calculate body mass index. Health shows BMI under Body Measurements when it has both values, or when a scale sends it.
- Date of birth and sex: Used for calorie estimates and for heart rate zones in the Workout app.
- Wheelchair: Turning this on changes the Stand ring to a Roll ring and switches how the watch counts activity.
Body fat percentage and lean body mass can also be logged under Body Measurements, either by hand or from a scale that measures them. They’re shown in Health but aren’t used for the watch’s calorie math.
Which method is right for you?
| Method | Effort | Best for |
|---|---|---|
| Health app on iPhone | Type each reading | Occasional updates and keeping calorie estimates accurate |
| Watch app Health Details | Type one number | Quickly fixing the weight the watch uses |
| Smart scale | Step on the scale | Daily tracking and long-term trends |
| Third-party watch app or shortcut | Enter it on your wrist | Logging without your phone |
Related: turn on Activity achievements on the Apple Watch.
Frequently asked questions
Can the Apple Watch weigh me?
No. No Apple Watch model has a sensor that can measure body weight. It only uses the weight stored in Health, which comes from you or a connected scale.
Does my weight change the calories my Apple Watch shows?
Yes. Weight is one of the details used to estimate Active Energy and resting calories, so an outdated weight makes your Move ring and workout calories less accurate.
How do I delete a wrong weight entry?
In Health, go to Weight > Show All Data, swipe left on the entry, and tap Delete. If the entry came from a scale, you may also need to delete it in the scale’s app so it doesn’t sync back.
Can I see my weight on my watch face?
Apple doesn’t include a weight complication. Some third-party weight apps add one, which shows your latest reading on supported watch faces.
How often should I log my weight?
For calorie accuracy, once a week or whenever your weight changes by a few pounds is enough. For tracking progress, many people weigh in at the same time each morning, which a smart scale makes easy.
Kermit Matthews runs Live2Tech from just outside Philadelphia. He is an IT specialist with over 20 years of experience, from a university help desk to small-business IT, IT management and his own consulting practice, and has written tech guides full time since 2020. Steps are checked against the current software on a real device or the maker’s official documentation. More about Kermit.