How old are you?
Enter a date of birth and calculate the age as of today or another date.
Private by design: your dates are processed in your browser and are not submitted to SDS.
Free Calculator
Free Age Calculator
Calculate an exact age in years, months, and days. You can use today or choose a specific date, then see total time lived and the countdown to the next birthday.
How It Works
Calculate your exact age in seconds.
The calculator measures completed calendar years and months first, then the remaining days. It also shows useful totals for a different view of the same time span.
Enter your birthday
Select the date you were born.
Choose a date
Use today or calculate your age on a past or future date.
See the breakdown
Get years, months, days, totals, birth weekday, and birthday countdown.
Age On A Specific Date
Find out how old you were — or will be — on another date.
Change the “Calculate age on” field to any valid date after the birthday. This is useful for forms, records, milestones, historical dates, school dates, employment dates, or simply checking a future age.
Age In Days & Weeks
See more than just years.
Along with calendar age, the calculator displays completed months, total weeks, and total days between the two dates. These totals can be useful when a more precise time span is needed.
Frequently Asked Questions
Age Calculator FAQ
How does this age calculator determine exact age?
It compares calendar dates to count completed years and months, then calculates the remaining days.
Can I calculate my age on a specific date?
Yes. Choose any date on or after the date of birth in the “Calculate age on” field.
Does SDS save my birthday?
No. The dates stay in your browser. SDS only records a general anonymous tool-use event for usage analytics.
How are leap-day birthdays handled?
For February 29 birthdays, the birthday countdown uses February 28 in years that do not contain February 29.
What does “total months” mean?
Total months means the number of fully completed calendar months in the calculated age, not an estimate based on an average month length.