Age Calculator
Enter a date of birth to see your exact age in years, months, and days — plus total days lived and time until your next birthday.
How to use the age calculator
- Enter the date of birth you want to calculate age for.
- "Calculate age as of" defaults to today's date — change it if you need age as of a different date.
- Click "Calculate" to see the exact age, plus total days and weeks lived, and days remaining until the next birthday.
Why use an age calculator?
Figuring out someone's exact age in years, months, and days by hand is fiddly, because months have different lengths and leap years throw off any simple "divide by 365" shortcut. This tool does the calendar math properly: it counts complete years, then complete months, then the remaining days, so the result is always accurate no matter which dates you pick. It's useful for filling out forms that ask for precise age, checking age-based eligibility rules as of a specific date, planning a birthday countdown, or just satisfying curiosity about how many days you've been alive. All calculations happen instantly in your browser and are for general informational purposes rather than legal or medical documentation.
How is my exact age calculated?
The calculator counts full years, then full months, then remaining days between your date of birth and the chosen date, correctly handling different month lengths and leap years rather than simply dividing total days by 365.
Why do I need to enter an "as of" date?
By default it's set to today, so you get your current age. Changing it lets you calculate age as of any other date — useful for eligibility rules, legal documents, or figuring out how old someone was on a specific day.
Does this handle leap years correctly?
Yes. The calculation is fully calendar-aware, so leap years, February's shorter length, and months of different lengths are all accounted for automatically.