Age Calculator: Exact Age in Years, Months and Days
Your age is the number of complete years, months and days between your date of birth and today. Someone born on 15 May 1990 is 36 years, 4 months and 6 days old on 21 September 2026.
Enter a date of birth to see the exact age.
How age is calculated
The calculator counts forward from the date of birth. It first counts the complete years that fit before the “age at” date, then the complete months after that, and finally the leftover days. Each step is shown in the Show the math panel so you can check it with a calendar.
If a birthday falls on the 31st and a month is shorter, the month is counted to its last day. For example, 31 January plus one month is 28 February (29 in a leap year), which is how most legal and administrative systems count too.
Age at another date
Change the “Age at” date to find someone's age on a past or future day, such as the date of a school cut-off, an insurance quote, a race entry or a job application. You can also see how old you will be at the next birthday and how many days remain until it, with a ring showing how far through the current year of life you are.
The totals in months, weeks, days and hours let you compare ages precisely or set milestones, such as your 10,000th day.
Leap years and different age systems
People born on 29 February have a birthday only in leap years. In other years this calculator treats the birthday as 28 February, while some places, such as the UK for legal purposes, use 1 March. Some cultures and traditions also count age differently. For example, the traditional Korean system counted a person as one year old at birth. This calculator uses the international standard, which counts completed years.
Your zodiac sign
Alongside the exact age, the calculator shows the Western (tropical) zodiac sign that falls on the date of birth, its symbol, and a few commonly cited personality traits associated with it. This is worked out purely from the calendar date — the twelve signs each cover a fixed range of dates, such as Capricorn from 22 December to 19 January — and is included as a bit of fun rather than anything scientifically validated.
Frequently asked questions
- How do I calculate my age from my date of birth?
- Subtract the birth year from the current year, and take one off if your birthday has not happened yet this year. The calculator also gives the extra months and days.
- How many days old am I?
- Enter your date of birth and read the total days. Someone born on 15 May 1990 has lived 13,278 days by 21 September 2026.
- When is my birthday if I was born on 29 February?
- In leap years it is 29 February. In other years it is counted as 28 February here, though some places use 1 March.
- Can I find age on a past or future date?
- Yes. Change the “Age at” date to any date, before or after today, as long as it is after the date of birth.
- What zodiac sign am I based on my birthday?
- Enter your date of birth above and it's shown alongside your age — for example, 15 May falls under Taurus (20 April to 20 May). It's based purely on the calendar date, using the Western (tropical) zodiac's standard date ranges.