Age Calculator
Find an exact age or the time between any two dates in years, months, weeks and days. Instant results, calculated in your browser.
About the Age Calculator
Our free age calculator works out exactly how old someone is, in years, months and days, from a date of birth. Switch to date-difference mode to measure the time between any two dates, such as the length of a project, a contract, a pregnancy or a countdown to an event. Results also show total months, weeks, days and hours, and the number of days until the next birthday.
The calculation follows the calendar, including leap years and months of different lengths, so results are accurate to the day. It all happens in your browser: the dates you enter are never uploaded or stored. You can also set a custom "age at" date to find out how old someone was, or will be, on a specific day.
How to Use the Age Calculator
Step 1
Enter a date
Choose a date of birth to calculate age, or a start date and end date for a date difference.
Step 2
Pick the comparison date
Leave it on today, or choose a specific date to find the age on that day.
Step 3
Read your result
See the exact difference in years, months and days, plus totals in weeks, days and hours, and the countdown to the next birthday.
Frequently Asked Questions
How is age calculated in years, months and days?
It counts the full years since the birth date, then the remaining full months, then the remaining days, following the calendar correctly.
How do I find the number of days between two dates?
Switch to date-difference mode, enter a start date and an end date, and you will see the gap in years, months and days along with the totals.
Does it account for leap years?
Yes, including February 29. For someone born on February 29, the next-birthday countdown uses February 28 in years that are not leap years.
Can I calculate age on a past or future date?
Yes. Change the "age at" date to any day to see how old someone was, or will be, on that date.
Is my date of birth stored anywhere?
No. The calculation runs in your browser, and the dates you enter are never uploaded, saved or shared.
Does the end date count as a day?
By default it does not, so you get the elapsed time between the two dates. Tick "include end date" to count both the first and the last day.