Biological age is a snapshot of how your body is performing compared to others your age. While your chronological age counts birthdays, your biological age looks at key biometrics to reveal whether you're trending younger, aligned with, or older than typical for your age group. It's just an estimate—but it can be a powerful way to understand how your body is doing.
We analyze five biomarkers that widely agreed upon research ties most closely to long-term health:
- Resting heart rate: a marker of cardiovascular fitness
- Heart rate variability: a marker of recovery and resilience
- Sleep duration: how much you're actually sleeping each night
- Daily activity: how much you're moving, measured in steps
- BMI: based on your height and weight
Each one is compared against benchmarks for your age and sex, and together they produce your biological age score.