Age Calculator

Two dates are all it takes, and the second one is optional.

1. Enter the Date of birth with the date picker or by typing it.
2. Leave Age on this date (empty = today) blank to get your age today, or fill it in to find your age on another day, such as a school cut-off or a future retirement date.
3. Read the age in the large result, then the rows below it.

The rows show the weekday you were born, total months, total weeks with leftover days, total days, total hours, your next birthday with the number of days to wait and the age you will turn, and your western zodiac sign. If the birth date is later than the second date, the tool asks you to check the order.

Age in years, months and days is counted on the calendar, not by dividing a day total, because months differ in length. The tool takes whole years first, then whole months, then the leftover days. When the day of the month on the target date is earlier than the birth day, it borrows one month and adds the length of the month before the target date.

Worked example: someone born on 15 June 1990 is, on 27 October 2026, 36 years, 4 months and 12 days old. That is 436 months, 1,897 weeks and 4 days, 13,283 days and 318,792 hours. Their next birthday is 15 June 2027, 231 days away, when they turn 37. Hours are simply days times 24, so they ignore clock changes and the actual time of birth.

The day before a birthday, the same person reads 35 years, 11 months and 30 days, so the new year of age starts exactly on the birthday. Set Age on this date to a past day to see how old you were then, for example when you started a job or finished school.

People born on 29 February are handled this way: in a year without a leap day the birthday is treated as 28 February, and the age counts up on that date rather than on 1 March. Rules for legal age differ by country, so check the one that applies.

Exact age matters whenever a rule has a cut-off date.

• Forms and applications that ask for age on a stated date, such as insurance, visas, exams and sports registrations.
• Young children, whose ages are usually quoted in months for the first two years.
• Legal thresholds, including the day someone reaches 16, 18 or 21.
• Pensions, where eligibility falls on a precise date.
• School and league cut-offs, where you set Age on this date to the cut-off day, such as 1 September, and read the age that applies on it.

This tool counts calendar time in the Gregorian calendar. Traditional East Asian age reckoning, for example, counts a baby as one year old at birth, so check the system an organisation uses. Zodiac signs come from fixed date ranges (Gemini, for instance, runs from 21 May to 20 June), and sources differ by a day at the edges. If your birthday falls on the 29th, 30th or 31st, compare the months-and-days split with the total days, because month-by-month counting is ambiguous when a month is shorter.

To measure the gap between any two dates, use the date difference calculator. The countdown timer can count down to the next birthday, the time converter turns days into hours or weeks, and for a baby not yet born the pregnancy due date calculator estimates the arrival date.