Why Your Birth Date Matters for the MyBioAge Index™
Learn how chronological age provides context for My Bio Age’s wellness estimate and how to check your birth date in Apple Health.
By My Bio Age
Your birth date provides the chronological age used in the MyBioAge Index™ and its comparison with calendar age. If the date is wrong, the comparison starts from the wrong reference point. Checking this detail is useful before interpreting a score.
Calendar age and estimated age are different
Chronological age is time since birth. The MyBioAge Index is a wellness estimate calculated from available health measurements and model reference information. Knowing the exact birth date improves the calendar input, but does not remove uncertainty in sensors, missing records or the model itself.
A score shown with a decimal place is not a claim that biological age can be known to that precision. Display precision and measurement accuracy are different things.
Check your details in Apple Health
- Open the Health app on iPhone.
- Tap your profile picture or initials.
- Open Health Details and review Date of Birth.
- Use Edit if the recorded date needs correcting.
Then reopen My Bio Age and let it refresh. Previously stored weekly results may not be recalculated immediately, so avoid treating a settings correction as a health improvement or decline.
How this relates to Pace of Aging
Pace of Aging describes the slope of weekly Index estimates over a selected time window. It is not simply the difference between your birth date and today. A change in reference details or scoring settings can affect comparability, so review the underlying weeks before interpreting a trend.
What to check alongside your birthday
- The dates covered by the weekly Index.
- Whether critical inputs are available.
- Whether your data source or app settings changed.
- Whether the apparent change persists across complete weeks.
My Bio Age uses your Health details locally. They are not sent to a clinical partner to compute your score. Treat the result as wellness context and use appropriate medical assessment for clinical questions.
Review your weekly wellness age estimate with its dates, inputs and data coverage. Download My Bio Age free on the App Store. The iPhone app is completely free, with no in-app purchases, subscription or account required. Your health data is processed privately on your iPhone.