Calories
The app estimates the active calories you burn while you jump. It works from your weight and your pace, and it counts only your time under the rope.
How the estimate works
The estimate uses the 2024 Adult Compendium of Physical Activities, which rates rope jumping by pace. A MET measures effort as a multiple of sitting still.
| Pace | METs |
|---|---|
| 90 jumps per minute or slower | 8.3 |
| 110 jumps per minute | 11.8 |
| 140 jumps per minute or faster | 12.3 |
Between those paces, the app blends the two nearest ratings, so a pace around 100 doesn’t leap from one rating to the next.
The app counts active energy only. It leaves out what your body burns at rest, the way Apple Health counts active energy. Each minute under the rope comes to (METs − 1) × 3.5 × your weight in kg ÷ 200, in kcal.
Only your time under the rope counts. Each gap between two jumps adds energy at your live pace, the JPM on screen. Rests, pauses and any gap of 1.5 s or more between two jumps add nothing.
For 70 kg (154 lb) at 120 jumps per minute, that comes to about 13 kcal for each minute under the rope.
Add your weight
Calories need your weight. Without one, KCAL shows “—” and the summary says “Add your weight in Settings to see calories.”
- Open Settings › Profile and tap the Weight card.
- Pick kg or lb, then turn the dial to your weight, to the tenth.
- Tap Save weight.
To take your weight from Apple Health instead, tap Connect on the Apple Health card of the same sheet. Apple’s sheet then asks for your weight and for saving your sessions in one go. See Apple Health.
The dial goes from 30 to 250 kg, or from 66 to 550 lb. You can also set your weight during onboarding, or from the session setup screen, where a No weight yet row stays until you add one.
Your weight is used only for calories. It stays on your devices and in your iCloud: see iCloud sync.
Which weight counts
When you have both, the newer one counts: your latest weigh-in in Apple Health, or the weight you entered. Saving a weight makes it the newest, so it counts until Apple Health records a newer weigh-in. To go back to Apple Health’s weight, tap Use on its card.
The Weight card says which one is in use, like “From Apple Health · Sep 12” or “Entered · today”.
The app reads your latest weigh-in from Apple Health when it opens, so a new one reaches your next session without a trip to Settings.
Each session keeps the weight it used. Changing your weight later leaves past sessions as they were.
Kilograms or pounds
Pick kg or lb under Units in Settings › Profile, or above the weight dial. The choice covers your weight and your ropes, and you can switch anytime. Until you pick, the app follows Apple Health’s unit for weight, or else your region’s.
Calories always show in kcal.
Reading the number
During a session, calories carry a small tilde, like “~48”. It’s the app’s mark for a number it estimated rather than measured.
“—” means there’s no estimate, because the app has no weight yet.
Where calories show
- During a session: KCAL in the bottom row, next to BPM, in work, rest and pause.
- In the summary and in each session’s report: KCAL among the key numbers, next to time and pace.
- On the story you share, after your longest run and your average BPM.
- In Apple Health, if you allow it: the estimate is saved as active energy with the session’s workout. See Apple Health.
On Apple Watch
On Apple Watch, the Watch measures the active calories itself, as it does for Apple’s own workouts, without your weight. Its live screens leave calories out, its summary shows them under KCAL · EST., and they’re saved with the workout in Apple Health. The Watch needs Apple Health for them: see Start a session.