How old you’d be if a “year” meant one orbit of that planet.
Age milestones by country
Typical ages in :region for voting, driving, and drinking.
Approximate only. Local laws can differ by state or region — not legal advice.
Heartbeats & breaths lived
Big, shareable estimates from your days alive.
Estimated heartbeats
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Estimated breaths
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Estimate only (~70 bpm, ~16 breaths/min). Not a medical measurement.
Days since last birthday
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Age in years
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Age in months
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Age in weeks
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Age in days
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Age in hours
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Age in minutes
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Age in seconds
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Born on
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Next birthday
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Age on next birthday
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Compare two ages
See who is older and by how many years, months, and days.
Birthdays you are tracking
Save birthdays to see everyone’s age and countdown to their next birthday.
No saved birthdays yet.
Saved only in this browser. Export a JSON or ICS file to keep a backup.
Learn more
Free online age calculator
How this age calculator works
This free online age calculator turns a birth date into exact calendar age, a next-birthday countdown, shareable milestones, and fun extras — from legal-age checks by country to estimated heartbeats and a printable age certificate.
01
Enter the birth date
Choose the date of birth. Optionally change the as-of date if you need age on a past or future day instead of today.
02
Click Calculate
See exact years, months, and days, days until the next birthday, life timeline, planetary ages, and country legal-age milestones.
03
Save, share, or print
Track birthdays locally, start a countdown or reminder, copy an embed widget, download a share card, or print a playful age certificate.
Why use an exact age calculator?
Many tools only show whole years. Exact calendar age matters for eligibility dates, school cutoffs, insurance, and personal milestones. This calculator also handles leap-day birthdays, compares two people, and adds shareable extras like heartbeat estimates and an age certificate — clearly marked when something is only an estimate.
What you get
Exact calendar age. Years, months, and days between birth and the as-of date — not just a rounded year count — plus the same span in weeks, hours, minutes, and seconds.
Birthday countdown. Days until the next birthday, weekday of birth, year progress, and one-click countdown on the Online Countdown tool.
Birthday tracker. Save birthdays in this browser, export JSON or ICS, remind one day before, pin the date on the year calendar, or copy a blog embed.
Legal-age milestones. See typical voting, driving, and drinking ages for the current locale — approximate only, not legal advice.
Heartbeat & breath estimates. Big, shareable estimates from days alive (~70 bpm, ~16 breaths/min), clearly labeled as estimates.
Age certificate. Print or download a playful “age certificate” for fun — not an official document.
Frequently asked questions
Exact age, birthdays, legal milestones, and shareable certificates.
How is exact age calculated?
We subtract the birth date from the as-of date using calendar years, months, and days — the same style of age you see on forms and IDs.
Can I calculate age on a date other than today?
Yes. Change the “As of” date to any day on or after the birth date. Use Today to reset it.
What happens if someone was born on February 29?
In non-leap years, the next-birthday countdown treats the celebration date as March 1 so the day still lands on a real calendar date.
Why do hours, minutes, and seconds look so large?
Those figures convert total whole days lived into hours (×24), minutes (×60), and seconds (×60). They assume midnight-to-midnight day boundaries, not a birth time of day.
Is “age in years” the same as exact age?
Exact age shows whole years plus leftover months and days. “Age in years” is the decimal span (total days ÷ average year length) for a continuous reading.
Is my birth date stored on a server?
No. The calculation runs in your browser. Birthday tracker entries stay in local storage on this device unless you export them.
Can I share an age calculation?
Yes. The birth date and as-of date are stored in the page URL hash. You can also download a share card, copy an embed widget, or print an age certificate.
Are voting, driving, and drinking ages official?
No. They are typical national ages for the site locale and can differ by region. Treat them as a quick reference — not legal advice.
How are heartbeats and breaths estimated?
We multiply days alive by average resting rates (~70 beats/min and ~16 breaths/min). The numbers are playful estimates only, not medical measurements.
Is the age certificate an official document?
No. It is a fun printable or downloadable keepsake from your calculated age. It has no legal standing.