Calculators / Age calculator
Age calculator
Calculate a calendar age on today’s date or any date you choose.
Dates stay in your browser. This is a calendar calculation, not a legal age determination.
How this age calculator works
Age is expressed as complete calendar months followed by the remaining days. Complete months are split into years and months: 37 complete months becomes 3 years and 1 month. Total elapsed days is shown separately.
Complete years = whole part of complete months ÷ 12
Months have different lengths, so dividing elapsed days by 365 or 30 does not give the same calendar result. This tool uses actual Gregorian calendar dates, including leap years.
Example: a date before your next birthday
From June 15, 1995 to September 16, 2026: 31 years, 3 months, and 1 day. The last complete monthly anniversary is September 15, 2026.
Birthdays at the end of a month
Each monthly anniversary starts from the original birth date. If the target month does not contain that day, the anniversary uses its last day. January 31 to February 28, 2025 is 1 month. January 31 to March 30, 2025 is 1 month and 30 days; the March 31 anniversary has not happened yet.
What happens with February 29?
February 29, 2020 to February 28, 2021 is 1 year under this tool’s end-of-month convention. Other tools or official rules may use a different anniversary. Do not use this result to decide legal eligibility, benefits, or a legal birthday.
Calendar dates, not birth times
The calculation ignores time of day and time zones. Two people with the same birth date get the same result for the same comparison date. “Use today” reads the current date from your device; you can change it manually.
Common questions
Can I calculate age on a future date?
Yes. Choose any comparison date on or after the date of birth, up to the year 9999.
Why can the leftover days be 30 or more?
The remaining days are counted after the last complete monthly anniversary. Because anniversaries are anchored to the original birth date, the remaining interval can span a short month.
Is my date of birth saved?
The calculator does not save inputs, put them in the URL, or send them to a calculation server. Closing or reloading the page resets the calculation.