Age Calculator
Enter your date of birth to see your exact age in years, months and days — plus how many days, weeks and months you have lived and a live countdown to your next birthday. Results update as you type.
To calculate your exact age, count the full years from your birth date to today, then the leftover whole months, then the remaining days. For instance, someone born 15 March 2000, measured on 23 June 2026, is 26 years, 3 months, and 8 days old.
Pick your date of birth to see your age.
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How to use the age calculator
Pick your date of birth in the first box. Your age appears instantly as whole years, months and days — there's no button to press and nothing is sent anywhere.
The age at this date field defaults to today, so you normally see your current age. Change it to any date to find out how old you were on a past day, or how old you will be on a future one.
Below the headline you'll see totals for how many days, weeks, months and hours you have lived, followed by a countdown to your next birthday.
Scoring a cognitive or language assessment? The chronological age calculator for test scoring uses the borrowing method behind WISC, WPPSI, Pearson and Brigance norm tables. Curious about your half birthday? Find it from the same birth date.
Everything runs in your browser using your device's clock — the dates you enter are never uploaded.
Common age questions
How do I calculate my exact age? Enter your birth date and the tool counts full years first, then the leftover months, then the remaining days — the way ages are normally stated.
How many days old am I? Check the “Days” total — it's the exact whole-day count between your birth date and today in your local time zone.
How old will I be on a certain date? Set the “age at this date” field to that date to see your age on any past or future day.
When is my next birthday? The countdown line shows how many days are left until your next birthday and which age you'll be turning.
What about a February 29 birthday? In non-leap years the anniversary falls on February 28, so your age and countdown stay correct every year.