Stax

Age Calculator

Calculate exact age in years, months, days with next birthday countdown.

How age is calculated

Age is calculated from date of birth to the current date — not just by subtracting years. A person born on March 15, 2000 who checks on February 1, 2025 is 24 years, 10 months, and 17 days old — not simply 24 or 25. This tool calculates the precise age accounting for month lengths and leap years.

Why exact age matters

Exact age is required for insurance policies, loan applications, passport documentation, school admissions (age cutoff dates), and medical assessments. The difference of even a few months can affect eligibility in many contexts.

Next birthday countdown

The tool also shows how many days until your next birthday — useful for planning or just satisfying curiosity. If your birthday has already passed this year, it counts down to next year's.

Frequently asked questions

How does the age calculator work?
It calculates the difference between your date of birth and today's date, accounting for varying month lengths and leap years. The result shows your exact age in years, months, and days — the same way age is calculated for official documents.
Does it account for leap years?
Yes. The calculator uses JavaScript's native Date object which correctly handles leap years (February 29) and varying month lengths.
What timezone is used?
The calculator uses your device's local date. If you're born on a day near midnight and your timezone differs from the location where your birth was recorded, there could be a one-day difference.
Can I calculate age for a future date?
This calculator only works for past dates (date of birth must be today or earlier). For a future date countdown, you'd use a different tool.

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