Age Calculator
Enter your date of birth to find your exact age in years, months and days.
What Is an Age Calculator?
An age calculator works out exactly how old you are — not just in years, but in years, months and days — based on your date of birth and today's date. It's useful for forms that ask for an exact age, for checking eligibility rules that depend on age, or simply out of curiosity.
How Age Is Calculated
The calculator compares your date of birth to today's date. It counts the number of full years that have passed, then the number of additional full months, and finally the remaining days. It also works out the total number of days and weeks you've been alive, which is handy for age-related calculations that use days rather than years.
Example
If you were born on 1 January 2000 and today is 22 August 2026, the calculator would show 26 years, 7 months, and 21 days, along with the equivalent total number of days and weeks.
Frequently Asked Questions
Is this age calculator accurate?
Yes. It uses your device's current date and calendar-based month and day counting, the same approach used in most official age calculations.
Can I calculate someone else's age?
Yes, just enter their date of birth. The calculator doesn't store or send the date anywhere — it's calculated directly in your browser.
Why can't I enter a future date?
A date of birth in the future isn't a valid age, so the calculator blocks it and asks for a valid past date instead.
Does it account for leap years?
Yes. Because the calculation is based on real calendar dates, leap years are automatically handled correctly.
How to check this result
Choose the date of birth and the comparison date carefully; the result changes if a birthday has not happened yet in that year.
Method and assumptions
The result counts completed calendar years, then remaining whole months and days.
Before making a decision
For legal, immigration, medical or school decisions, confirm the result against the official rule that applies in your location.
Completed birthdays and calendar age
Method and inputs
The tool compares the birth date with today’s date on your device. Completed years increase on a birthday; months and remaining days describe the interval after that anniversary. Total days are counted separately using calendar dates.
Worked example
Someone born on 1 January 2000 is 26 years, 7 months and 21 days old on 22 August 2026. Before 1 January 2026, that person had completed only 25 years.
Limits and common mistakes
Keep your device date correct. Month-end dates and 29 February need a stated anniversary convention; this tool uses JavaScript calendar rollover, which can move an anniversary into the next month. Legal eligibility may use different rules.
Can I use the result as legal proof of age?
No. It is a calendar estimate, not identity verification. An organization may require documents and apply its own jurisdiction’s birthday rules.
Content updated: 2026-10-03.