Enter a date of birth and your exact age appears in years, months and days, with the totals in months, weeks and days, the weekday you were born on and how many days are left until your next birthday. Change Age on this date to find someone's age on any past or future date, such as an exam cut-off date or the day a form will be checked.
How the years, months and days are counted
The calculator counts whole years, then whole months, then the days left over, the same way you would on a calendar. Someone born on 15 May 1990 is 36 years, 5 months and 23 days old on 7 November 2026: 36 birthdays have passed, the last one on 15 May 2026, then five monthly steps to 15 October, then 23 more days.
Months have different lengths, which causes small surprises. From 31 January to 29 February is 29 days, because there is no 31 February to complete a month. From 31 January to 1 March is 1 month and 1 day. This is the standard rule used by most date libraries and age calculators, so results match what other careful tools give.
Birthdays on 29 February
People born on 29 February have a real birthday only in leap years. In other years this calculator counts the birthday on 1 March, so the age goes up a year on 1 March and the countdown points to 1 March. Rules differ between countries and organisations, and some use 28 February instead, so check the rule if an exact date matters for something official.
Age for forms and cut-off dates
Exams, school admissions, sports categories and job applications often set an age limit on a fixed date, such as "at least 18 on 1 January" or "under 30 on the last date of application". Set Age on this date to that date to see the exact age the form will use. Ages are worked out from calendar dates only, with no time of day, so the result doesn't change with your time zone.
The totals
Total days counts every day from the date of birth to the chosen date. Total weeks divides that by seven and shows any spare days, and total months counts complete months. These are handy for baby milestones, which are usually given in weeks and months, and for curiosities such as your 10,000th day.
Nothing you enter is sent anywhere. For working with timestamps and time zones, try the Unix Timestamp Converter, and for quick sums, the Percentage Calculator or EMI Calculator.
