Calculate your exact age in years, months, and days
Use this free age calculator to quickly determine your age in years, months and days from your date of birth. The tool accounts for leap years and different month lengths.
How it works
Enter your date of birth using the date picker.
Click "Calculate Age" or press Enter to get your exact age.
The tool calculates years, months and days and shows days until your next birthday.
Frequently asked questions
Is this calculator accurate for leap years?
Yes — the calculator accounts for leap years and uses calendar month lengths to compute exact years, months and days.
Can I use this for birthdays in different time zones?
The calculator uses the client machine's local date. For precise timezone-aware calculations, convert the date to the target timezone before using the tool.
What if I only know the year or month?
For best accuracy provide the full date (YYYY-MM-DD). If you only have a year or month, results will be approximate.
How this age calculator works
Our calculator determines your age by comparing your date of birth with today’s date and breaking the difference down into years, months and days. It takes into account the exact number of days in each month and adjusts for leap years so the result is precise. The calculation is performed entirely in your browser — no personal data is sent to our servers.
Example
If a person was born on March 1, 1990 and today is September 24, 2025, the calculator will compute complete years first, then remaining months and days. It also computes how many days remain until the next birthday.
Common use cases
Confirming your exact age for official forms or records.
Calculating age differences between two people.
Counting days until a milestone birthday or anniversary.
Privacy and accuracy
We do not collect or store any dates you enter. All calculations run locally in your browser for privacy and speed. For timezone-sensitive use cases (for example, when the exact time of birth matters across zones), convert the date to your target timezone before using this tool. For best accuracy enter a full date (YYYY-MM-DD).
Age calculation explained (methodology & accuracy)
This section explains how age is calculated and why precision matters. The calculator computes full years first, then calculates remaining months and days by considering the varying lengths of calendar months and leap year rules. This approach mirrors standard civil date arithmetic used in legal and administrative contexts.
Step-by-step
Start with the birth date and today's date.
Subtract years to get the number of full years.
Subtract months (borrowing from years if needed) to find full months.
Subtract days (borrowing from prior month length when required) to find remaining days.
Why month lengths and leap years matter
Months have between 28 and 31 days and leap years add a day in February. A simple day-count divided by 365 can be off by a day or more; by using calendar-aware arithmetic the result becomes exact for common requirements like age verification or eligibility checks.
Real-world examples
Use the example above to see how years, months and days are derived. For milestone planning (e.g., 18th or 21st birthdays) rely on the full-year calculation; for countdowns use the provided “days until next birthday” metric.
SEO & content relevance
Adding clear explanations, examples and privacy statements helps search engines understand the page topic and increases the chance of appearing for queries such as "how to calculate age", "age in years months days" and "days until birthday." Internal links to use cases and privacy strengthen on-page signals.
Limitations
The calculator is intended for civil-date calculations. When exact birth time and timezone are critical (for astrological charts, legal timestamping, or medical records) consider using a timezone-aware utility with full datetime inputs.