Biological-Age Clocks

MRI-based brain age estimates how old your brain looks biologically, from brain-imaging features. Those features include cortical thickness, white-matter integrity, gray-matter…

CausAge is an epigenetic clock built to fix a deep flaw in the clocks that estimate your biological age. It was introduced by Ying, Gladyshev and colleagues (preprint 2022;…

DamAge and AdaptAge are 'causality-aware' epigenetic clocks. Kejun Ying and colleagues built them in the Gladyshev lab at Harvard / Brigham and Women's Hospital (Nature Aging,…

The DNAm Skin & Blood clock was published by Horvath and colleagues in 2018. It estimates your epigenetic age from 391 CpG sites. Those sites were picked from methylation arrays…

DNAmTL is an epigenetic estimate of your telomere length. It is derived from the methylation levels of 140 CpG sites in blood DNA. It was trained with elastic-net regression,…

DunedinPACE (Pace of Aging Calculated from the Epigenome) is an epigenetic clock published in 2022 by Belsky and colleagues. Unlike most clocks, it estimates your rate of…

Your epigenetic age estimates how old your body seems biologically, read from chemical tags on your DNA. Certain spots on the genome (CpG sites) gain or lose methyl groups over…

GlycanAge is a biological-age test based on the sugar coating of your antibodies. Your antibodies (immunoglobulin G, or IgG) carry small branched sugar chains called N-glycans.…

GrimAge is a second-generation epigenetic clock. Lu et al. introduced it in 2019, with Steve Horvath as senior author. Instead of predicting your chronological age, it is trained…

The Hannum clock is a blood-based epigenetic age estimator, published by Gregory Hannum and colleagues in 2013. It uses DNA-methylation levels at 71 CpG sites, taken from…

The Horvath clock is a multi-tissue epigenetic age estimator, published by Steve Horvath in 2013. It uses DNA-methylation levels at 353 CpG sites to predict your chronological…

iAge is an 'inflammatory age' score, introduced by Sayed and colleagues (2021, Stanford). It uses a deep-learning model, trained on a panel of 50 blood cytokines and chemokines,…

The Klemera-Doubal method (KDM) is a statistical algorithm that estimates your biological age from clinical biomarkers. It works by minimizing the squared distances between a set…

Leukocyte telomere length (LTL) is the average length of the repetitive TTAGGG caps on your chromosome ends, in your white blood cells. It is measured in kilobases (kb) and used…

OMICmAge is a biological-age clock read from your DNA methylation. The clever part: it is trained to also reflect your proteins, metabolites, and routine lab values, without…

PCGrimAge applies the same noise-reduction trick to the GrimAge clock. (The trick comes from Higgins-Chen et al., 2022.) The result is a more technically stable version of one of…

PCPhenoAge is a technically refined version of the DNAm PhenoAge clock, introduced by Higgins-Chen and colleagues (2022). The upgrade: it runs principal-component (PC) regression…

PhenoAge is a composite measure of your biological age. Levine and colleagues developed it in 2018. The original version is blood-based. It blends nine clinical markers with your…

ProAge and similar 'proteomic age' clocks estimate your biological age from the levels of hundreds to thousands of proteins in your blood. The proteins are measured by…

RetinaAge is a biological-age clock built from retinal fundus photographs. A deep-learning model is trained to predict your age from the features of your optic disc, fovea, and…

SystemsAge is a methylation-based biological-age clock that looks at multiple body systems. Sehgal et al. introduced it (2025, Nature Aging, Levine lab). From a single blood…