Bio-age calculator · free, no signup

How old are you, really?

Eight inputs. Thirty seconds. The same engine that runs in the Thier iPhone app on real users, just stripped down to what you can answer without a wearable. Argue with the result - every coefficient is published.

Bio age so far

y
Fill in your details to see the live estimate

About you

Cardio + sleep

Apple Watch / Garmin show this. Average for 30s ~36, athletic 50+.
Your projected bio age
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Calculating…
Chrono age
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Bio age
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Range based on the inputs you provided.

Want to see what changing one input would do? Try the What-If simulator. Curious about the science? Read the methodology.