Age Calculator
Get exact age in years, months, days & hours
About Age Calculator
An age calculator determines the exact time elapsed between a birth date and today (or any target date). This free Age Calculator gives you your precise age in years, months and days — plus the total number of days you've lived and a countdown to your next birthday. Perfect for official forms, medical references, event planning, and any time you need exact age or date difference calculations.
How to Use Age Calculator
- 1Enter your date of birth using the date picker.
- 2The calculator automatically uses today's date as the end date (or enter a custom date).
- 3Your exact age in years, months and days appears instantly.
- 4See additional breakdowns: total days lived, hours, and upcoming birthday countdown.
Common Use Cases
Use the "Custom Date" mode to calculate age between any two dates — useful for calculating how long a project ran, how old a document is, or days until a deadline.
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Frequently Asked Questions
How is exact age calculated in years, months and days?
Exact age calculation counts complete calendar months, not just 30-day periods. From February 15 to March 15 is exactly 1 month, regardless of how many days are in February. Years work similarly — from January 31, 2000 to January 31, 2026 is exactly 26 years.
Why does my age differ by a day sometimes?
Age discrepancies of one day typically happen around birthdays and month boundaries due to timezone differences and how different systems handle the "birthday" day itself. This calculator uses your local timezone. For official documents, use the date in your legal jurisdiction.
How do I calculate someone's age for a government form?
Most government forms require age as of a specific date (the form submission date or a reference date). Enter the date of birth and set the "end date" to the required reference date. The years shown is the official age for that date.
Can I calculate the age of a pet?
Yes. Enter your pet's birth date the same way. Note that "pet years vs human years" conversions (e.g. the "7 dog years = 1 human year" myth) are approximate and breed-dependent — this tool shows the actual calendar age, not a species-converted age.