The idea
A birthday tells you how many years you have — a tidy, round, slightly abstract number. But you don’t live in years. You live in heartbeats and breaths and mornings, and those counters have been running quietly since the day you arrived. This instrument simply reads them out.
Seen as totals, an ordinary life looks astonishing. A few billion heartbeats. Hundreds of full moons. A double-digit pile of years spent entirely asleep. Nothing about you changes when you press the button — but the scale of what you’ve already done becomes visible.
How it’s measured
The day count is real calendar math: we take your date of birth and today’s date and count the exact days between them, leap years included. Everything else multiplies that count by well-documented averages: a resting heart rate of about 72 beats per minute (a normal adult range is roughly 60–100), around 16 breaths per minute, about 15 blinks per waking minute, and sleep at roughly a third of each day. Full moons use the true lunar cycle of 29.53 days, and “trips around the Sun” uses the astronomical year of 365.2425 days.
These are population averages, not medical measurements — think of the result as a well-made estimate with a wink, not a lab report.
Questions, answered
Does this account for leap years?
Yes. The day count comes from real date arithmetic between your birthday and today, so every leap day you have lived through is included automatically.
Why do other sites give slightly different numbers?
The day count should match anywhere; the body statistics depend on which averages a site chooses. We use 72 heartbeats and 16 breaths per minute and state our assumptions openly, so you can judge the estimate for yourself.
Is my birthday stored anywhere?
No. The calculation runs entirely in your browser and nothing is sent to a server. If you share your result, the link itself carries the inputs you chose to include — that is all.