About this site

This site takes one thing — your date of birth — and works out as much as it usefully can from it. Around a hundred and forty facts, from the exact second of your age to the phase of the moon on the night you were born.

Nothing you type leaves your device

There is no account and no server doing the sums. Every calculation runs in your own browser, which is why results appear instantly and why your birthday is never stored anywhere.

Where the numbers come from

Dog years use the 2019 UCSD/NHGRI epigenetic study, not the 1950s “multiply by seven” myth. Moon phases use the standard synodic-month calculation. Planet ages use NASA's published orbital periods. Zodiac signs, birthstones and birth flowers follow the conventional tables. Population, inflation and CO₂ are published figures interpolated between anchor years.

What is estimated

Some figures are population averages rather than facts about you — heartbeats, breaths, steps, meals, hours slept, life expectancy. Every one of those is marked est. Birthday rarity is currently modelled from published seasonal birth patterns rather than raw records, and will be replaced with the real data.

Name meanings

Name origins and meanings are compiled from Wiktionary, which is published under CC BY-SA, alongside a hand-checked set of the most common names. Where the two disagree, the hand-checked version is shown. Many names are still missing — there are tens of thousands in use worldwide and this is an ongoing job.

Corrections welcome

If a fact here is wrong, or your name is missing from the name database, we would genuinely like to know.