Age calculator
Calculate exact age in years, months and days and the time until the next birthday.
Private: it runs in your browser and what you type is never sent anywhere. How to check it
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How we handle your data →How to use this tool
- Enter the date of birth.
- Leave the calculation date empty to use today, or enter another.
- Calculate and review years, months, days and the next birthday.
An example you can verify
Calculate exact age and the time left until the next birthday.
Example input
Birth 1990-05-15, calculation date 2026-10-15.
Expected result
Age of 36 years, 5 months and 0 days; 13,302 days lived; next birthday on 15 May 2027.
Check the result with a date you know well, such as an anniversary. If you use a future reference date, confirm it is the one you intend.
Age calculator: uses and practical guidance
Age in years, months and days looks trivial, but it depends on how months of different length are counted. This tool subtracts the birth date from the reference date using the real calendar: when the day of the month has not been reached yet, the number of days in the previous month is borrowed. A person born on 31 December is therefore 35 years and 1 day old on 1 January 2026, not an approximation obtained by dividing by 30.
Besides complete age, total days and complete weeks are shown, which helps with forms that request age in days or with milestone calculations. The weekday of birth comes from the calendar itself. For the next birthday the month and day are kept; someone born on 29 February celebrates on 28 February in common years, a usual convention when the calendar lacks that date.
The calculation uses calendar dates without times or time zones, so it does not change if you travel or daylight saving time shifts. It is not suitable for official procedures that define age differently, such as some minimum-age or retirement rules; in those cases consult the authority’s criterion. Data never leaves your browser and is not stored.
A frequent mistake when calculating an age is counting every month as thirty days or dividing total days by 365. Both shortcuts give results that drift from the real age, especially near a birthday. If you need to compare two people, use the same reference date for both. If you are preparing a procedure that asks for age on a specific date, enter that date instead of leaving the field empty, because today’s result will change tomorrow. Keep the screenshot or copied text next to the document so you can justify the figure later.
A practical check before using the result
Try a person born on 29 February and a reference date after 28 February in a common year: the next birthday should fall on the following 28 February. Then check a known case, such as a wedding anniversary, and confirm years, months and days match your manual count.
Settings and limits
Choose a date of birth and, optionally, a reference date; when empty, today is used. The result shows complete years, months and days, total days lived, the weekday of birth and the next birthday date. Dates are compared as calendar days, without times or time zones.
Frequently asked questions
What happens for someone born on 29 February?
In common years the next birthday is counted on 28 February. Complete years, months and days use the real calendar length of each month.
Is it free, and do I need to sign up?
Yes, it is free. You do not need to sign up, create an account or install an app, and there is no daily quota: open the tool and use it. The only limits are file sizes, which protect your device’s memory.
Is my data sent to any server?
No. What you type or paste is processed in your browser’s memory and is not sent to any server. You can check it in the browser’s Network tab or by going offline after the page has loaded.