Horvath clock

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 age, across more than 50 tissues and cell types, with a median error of about 3.6 years. It is the most-cited epigenetic clock, and it is well validated as a predictor of chronological age. But its link to mortality and disease is weaker than that of later, mortality-trained clocks, like GrimAge.

Last reviewed: June 22, 2026

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