Age Calculator
Enter a date of birth and instantly see the exact age in years, months and days — plus the next birthday countdown and the day of the week you were born.
Fun age facts
- You'll live about 27,375 days in a 75-year lifespan.
- A billion seconds of life corresponds to just under 31.7 years — a milestone worth celebrating.
- People born on 29 February (leap day) only have a "true" birthday once every 4 years.
- In South Korea, everyone traditionally ages one year on New Year's Day rather than on their birthday, making the "Korean age" 1–2 years higher than the international standard.
Frequently asked questions
How is my exact age calculated?
The calculator counts the number of complete years, months, and days between your birth date and today (or a custom target date). It accounts for different month lengths and leap years so the result is always precise.
What day of the week was I born?
The calculator uses the Gregorian calendar algorithm to determine which day of the week any date falls on and displays it with your results.
Can I calculate the age on a specific date?
Yes — switch from 'As of today' to 'Custom date' to see exactly how old you will be (or were) on any date in the past or future.
Why is the month/day count sometimes surprising?
Months have different lengths (28–31 days), so a 'month' in age terms always means a complete calendar month. If your birthday is the 31st and the current month has 30 days, the calculator uses the last day of the month for consistency.
All calculations run in your browser. No personal data is stored or transmitted.