Age Calculator
Age calculator — enter your date of birth to find out exactly how old you are in years, months, days, weeks, and hours. This free age calculator also shows your next birthday countdown. Whether you need your precise chronological age for a school enrollment form, a medical assessment, or you’re simply curious, the result is calculated to the exact day.
How to Calculate Your Age
Calculating your exact age is simple: subtract your date of birth from today’s date. Our age calculator handles the complexity of different month lengths (28–31 days) and leap years automatically, ensuring accuracy down to the day.
Precise age calculation matters more than most people realize. Schools use chronological age for kindergarten enrollment cutoffs, pediatricians track infant development by weeks and months against CDC milestone guidelines, and the Social Security Administration determines retirement benefits based on your exact birth date — not just birth year.
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Calculate your exact age in days.
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Find your exact age in weeks.
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Calculate age in years, months, and days format.
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Frequently Asked Questions
Enter your date of birth in the calculator above. The calculator will automatically determine your exact age in years, months, and days by comparing your birth date to today’s date. This accounts for leap years and varying month lengths to ensure complete accuracy.
To find your age from just a birth year, enter any date in that year (like January 1st of that year) into our calculator. However, for a precise age, you’ll need your complete birth date including month and day, as age varies by a year depending on whether your birthday has occurred yet this year.
Chronological age is your exact age calculated from your date of birth. It’s expressed in years, months, and days (format: Y;M;D). This is different from developmental age or mental age, and is commonly used in educational settings, psychological assessments, and medical evaluations to ensure fairness and accuracy.
Use our “How Many Days Old Am I” calculator to find your exact age in days. Simply enter your birth date and the calculator will show your total number of days lived. This is a fun way to see just how much of your life you’ve actually experienced!
Your half birthday is exactly 6 months before or after your actual birthday. Use our Half Birthday Calculator to find the exact date. For example, if you were born on March 15, your half birthday would be September 15. Some people celebrate half birthdays as a fun alternative to their actual birthday!