Vitality Score Methodology

Formula version documented from the app implementation on September 4, 2026.

The Vitality Score is a 0–100 wellness indicator calculated from Apple Health data that a user permits Health Genie to read. It is designed to summarize recent movement and recovery-related signals. It is not a clinical score.

Inputs and baselines

InputComparison baselineFallback when history is unavailable
Steps todayRolling 7-day average7,500 steps
Resting heart rate recorded for todayAverage of the available resting-heart-rate history loaded for up to 60 days72 bpm is used for today’s input when no current-day value exists, and for the baseline when no history exists
Last night’s sleep, when availableRolling 7-day average7.5 hours

The fallback values are product defaults used so the app can produce an initial result before enough personal history exists. They are not medical targets or diagnoses.

Formula without sleep

When no positive sleep-duration value is available, the score uses steps and resting heart rate:

step trend = min((today’s steps ÷ step baseline) × 100, 120)
heart-rate trend = (resting-heart-rate baseline ÷ today’s resting heart rate) × 100
raw score = (step trend × 0.55) + (heart-rate trend × 0.45)

Formula with sleep

When a positive sleep-duration value is available, the weights change and sleep is added:

sleep trend = min((last night’s sleep ÷ sleep baseline) × 100, 110)
raw score = (step trend × 0.45) + (heart-rate trend × 0.35) + (sleep trend × 0.20)

The final score is rounded to the nearest whole number and limited to the range 0–100. Capping step and sleep trends limits how much a single unusually high value can inflate the result.

Score labels

ScoreLabel
70–100Great
40–69Fair
0–39Low

These labels describe the product’s own score bands. They are not clinical categories and should not be interpreted as proof that someone is healthy or unwell.

What the score does not use

This version of the Vitality Score does not use HRV, blood oxygen, ECG results, wrist temperature, medications or medical history. AI does not calculate the score; the deterministic formula above does. AI may be used separately to turn selected metrics into a plain-language brief.

Known limitations

Medical limitation: Do not use the Vitality Score to diagnose a condition or decide whether to seek medical care. Symptoms or an unusual heart-rate reading should be discussed with a qualified healthcare professional.

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