Age Calculator
Enter your date of birth to see your exact age in years, months and days. It also shows the total days and weeks you have lived, the day of the week you were born, and how many days are left until your next birthday.
Dates
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Years
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Months
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Days
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Total days lived
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Days until next birthday
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Weeks lived
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Day you were born
How It Works
The calculator counts how many whole years have passed since your date of birth, then the whole months after that, then the days left over. A person born on 15 March 2000 is 26 years, 2 months and 30 days old on 14 June 2026. Total days lived is the plain count of calendar days between the two dates, so leap years are included automatically; two people who are both 26 can have lived different numbers of days. On average a year has 365.2425 days, which is why 30 years is about 10,957 days. By default the end date is today, but you can type any date to see your age on a day in the past or the future, for example to check someone's age on the date of an event or an application. For a birthday on 29 February, this calculator treats the birthday as 28 February in years that are not leap years; rules for 29 February birthdays differ between countries.
Formula
Age = the date you are measuring to minus your date of birth, counted as whole years, then whole months, then days. Days lived = the number of calendar days between the two dates. Days to next birthday = your next birth month and day minus the date you are measuring from.
Worked Examples
Three dates worked out the same way as the calculator: complete years first, then complete months, then days. Total days counts every calendar day between the two dates.
| Born | Measured on | Age | Total days |
|---|---|---|---|
| Wednesday, 15 March 2000 | 14 June 2026 | 26 years, 2 months, 30 days | 9,587 |
| Saturday, 12 October 1985 | 1 January 2027 | 41 years, 2 months, 20 days | 15,056 |
| Sunday, 4 July 1976 | 15 August 2026 | 50 years, 1 months, 11 days | 18,304 |
Age in Months, Weeks, Days and Hours
A quick reference for a birthday age, using 365.2425 days a year. Your own totals will be a little different because they depend on how many leap days fell in your life.
| Age | Months | Weeks | Days | Hours |
|---|---|---|---|---|
| 1 years | 12 | 52 | 365 | 8,760 |
| 5 years | 60 | 261 | 1,826 | 43,824 |
| 10 years | 120 | 522 | 3,652 | 87,648 |
| 13 years | 156 | 678 | 4,748 | 113,952 |
| 16 years | 192 | 835 | 5,844 | 140,256 |
| 18 years | 216 | 939 | 6,574 | 157,776 |
| 21 years | 252 | 1,096 | 7,670 | 184,080 |
| 30 years | 360 | 1,565 | 10,957 | 262,968 |
| 40 years | 480 | 2,087 | 14,610 | 350,640 |
| 50 years | 600 | 2,609 | 18,262 | 438,288 |
| 60 years | 720 | 3,131 | 21,915 | 525,960 |
| 65 years | 780 | 3,392 | 23,741 | 569,784 |
| 70 years | 840 | 3,652 | 25,567 | 613,608 |
| 80 years | 960 | 4,174 | 29,219 | 701,256 |
Frequently Asked Questions
How is exact age calculated?
Exact age counts the complete years since the date of birth, then the complete months after that, then the remaining days. Only completed units count. Born on 15 March 2000 and measured on 14 June 2026, the age is 26 years, 2 months and 30 days.
How do I calculate my age on a specific date?
Enter your date of birth, then change the second date from today to the date you care about, such as the first day of a course, the date of an event or a future date. The calculator returns your age on that day. This is how you check an age requirement or work out how old someone will be next year.
How many days old am I?
The calculator shows total days lived, counting every calendar day from your birth date to the end date. As a rough guide, multiply your age in years by 365.2425: a person aged 30 has lived about 10,957 days, and one aged 50 about 18,262.
Why does my age differ from simply subtracting the birth year?
Subtracting years overstates your age by one if your birthday has not happened yet this year. Exact age checks whether this year's birthday has passed. Someone born in 1990 is 35 until their 2026 birthday, even though 2026 minus 1990 is 36.
What happens with a 29 February birthday?
The date exists only in leap years, so in years that are not leap years this calculator treats the birthday as 28 February: someone born on 29 February 2000 turns 26 on 28 February 2026, and the days until the next birthday count to 28 February 2027. Countries and organisations handle it differently (some use 28 February, others 1 March), so check the rule that applies to you if the exact day matters.
How many days are in a year for age calculations?
Total days lived uses the real calendar, so leap years count as 366 days. Over a long period the average is 365.2425 days a year, which is the figure used for rough conversions between years and days.
Is there a legal age I should use for a particular purpose?
Legal ages differ by country and by purpose, such as voting, driving, drinking, signing contracts or claiming a pension, and in some countries by state or province. This calculator tells you how old someone is on a date; it does not decide what that age allows. For retirement ages, see the Days Until Retirement calculator.