# Biological Age vs Chronological Age

Chronological age is simply the years since you were born. Biological age estimates how old your body actually is, from markers like blood biomarkers, epigenetic "clocks" (e.g. DunedinPACE, GrimAge) and fitness. The two often differ by 10 to 15 years, and it's biological age, not your birthday, that tracks more closely with disease risk and lifespan. The useful part: chronological age only moves one way, but biological age can be slowed, and on some markers partly reversed, by how you live.

Why your body's age matters more than your birthday

## On this page

- What is Chronological Age?
- What is Biological Age?
- How is Biological Age Measured?
- Why Does Biological Age Matter?
- Can You Change Your Biological Age?

## FAQ

- How accurate are biological age tests?
- How often should I test my biological age?
- Can my biological age be lower than my chronological age?
- Is it possible to have a higher biological age when young?

## Sources

- Horvath S. (2013). DNA methylation age of human tissues and cell types. Genome Biology. https://doi.org/10.1186/gb-2013-14-10-r115
- Levine ME, Lu AT, Quach A, et al.. (2018). An epigenetic biomarker of aging for lifespan and healthspan (PhenoAge). Aging (Albany NY). https://doi.org/10.18632/aging.101414
- Lu AT, Quach A, Wilson JG, et al.. (2019). DNA methylation GrimAge strongly predicts lifespan and healthspan. Aging (Albany NY). https://doi.org/10.18632/aging.101684
- Belsky DW, Caspi A, Corcoran DL, et al.. (2022). DunedinPACE, a DNA methylation biomarker of the pace of aging. eLife. https://doi.org/10.7554/eLife.73420
- Fitzgerald KN, Hodges R, Hanes D, et al.. (2021). Potential reversal of epigenetic age using a diet and lifestyle intervention: a pilot randomized clinical trial. Aging (Albany NY). https://doi.org/10.18632/aging.202913
- Fitzgerald KN, Hodges R, Hanes D, et al.. (2024). Corrigendum: Potential reversal of epigenetic age using a diet and lifestyle intervention. Aging (Albany NY). https://doi.org/10.18632/aging.205700
- de Brito LB, Ricardo DR, de Araújo DS, Ramos PS, Myers J, de Araújo CG. (2012). Ability to sit and rise from the floor as a predictor of all-cause mortality. European Journal of Preventive Cardiology. https://doi.org/10.1177/2047487312471759
- Cruz-Jentoft AJ, Bahat G, Bauer J, et al.. (2019). Sarcopenia: revised European consensus on definition and diagnosis (EWGSOP2). Age and Ageing. https://doi.org/10.1093/ageing/afy169
- Zhao Y, Yang H, Jiao R, Wang Y, Xiao M, et al.. (2024). Phenotypic age mediates effects of Life's Essential 8 on reduced mortality risk in US adults. Precision Clinical Medicine. https://doi.org/10.1093/pcmedi/pbae019

_Full guide: https://longevity-germany.com/en/guide/biological-age_

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_Canonical: https://longevity-germany.com/en/guide/biological-age · Part of Longevity Cities · Updated 2026-05-23_