Age Calculator
Calculate exact age in years, months, and days from date of birth.
About this tool
Need to know exactly how old you are — not just in years, but in months and days? The Age Calculator gives you precise, calendar-accurate results in an instant.
How the Age Calculator works
The Age Calculator computes your chronological age from your date of birth to today (or any reference date). It displays the result in years, months, and days, correctly handling month boundaries, leap years, and February 29 birthdays.
How to use this tool
- Enter your date of birth using the date picker.
- Optionally enter a different reference date — the default is today's date.
- Click 'Calculate' to see your exact age in years, months, and days.
Common use cases
Verifying age eligibility for applications and forms
Calculating exact age for medical or insurance purposes
Finding the precise age difference between two people
Determining school grade eligibility based on age cutoffs
Examples
- Someone born on March 15, 1990 is calculated as 35 years, 3 months, and 18 days old on July 3, 2025.
- A February 29, 2000 birthday correctly advances the year count on March 1 in non-leap years.
Tips & best practices
- The calculator uses strict calendar arithmetic — your age increments on your exact birthday date, not at midnight on January 1.
- For February 29 birthdays in non-leap years, the calculator follows the standard convention of using March 1 as the birthday.
- You can use a future reference date to project your age on a future birthday or milestone date.
Common mistakes to avoid
❌ Confusing 'years old' with 'birth year subtracted from current year' — someone born in December may appear to be a year older if you only subtract years.
❌ Forgetting that age calculation depends on whether the birthday has passed in the current year.
Frequently Asked Questions
Does this calculator include months and days?
Yes. Results show full years, remaining months, and remaining days — not just the year count.
How are leap year birthdays handled?
For February 29 birthdays in non-leap years, age advances on March 1 — the standard legal convention in most jurisdictions.
Can I calculate age for a past date?
Yes. Set the reference date to any date in the past to find age on that specific day, such as a historical milestone or anniversary.
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