Age calculator
Enter the date of birth, and the age is worked out for whatever day you choose.
Age in years
36
36 years, 9 months and 3 days
- Born on aMonday
- Next birthday1 January 2027
- Days to go89turning 37
The same age in other units
- Months441
- Weeks1,917
- Days13,425
- Hours322,200
- Minutes19,332,000
When you reach
| Age | Date |
|---|---|
| 18 | 2008-01-01passed |
| 20 | 2010-01-01passed |
| 30 | 2020-01-01passed |
| 40 | 2030-01-01 |
| 50 | 2040-01-01 |
| 60 | 2050-01-01 |
| 65 | 2055-01-01 |
| 70 | 2060-01-01 |
| 75 | 2065-01-01 |
| 80 | 2070-01-01 |
| 90 | 2080-01-01 |
| 100 | 2090-01-01 |
The dates clamp to the last day of the month, so someone born on 29 February reaches the age on the 28th in years that are not leap years.
How it works
Age is counted as a calendar difference, the way people state it. Someone whose birthday was yesterday is a year older than someone whose birthday is tomorrow, no matter how many days have passed since birth.
That means the months are not all the same number of days. From 31 January to 1 March is one month and one day, because there is no 31 February, and the same clamping applies to age.
Anyone born on 29 February has a birthday only every fourth year. Here the age goes up on 28 February in years that are not leap years, so the birthday stays in February. Countries can have different rules for when someone born on 29 February reaches an age, so check the rule that applies if the date matters for something official.
Weeks, days, hours and minutes are counted straight through from the date of birth, so they are not clamped to the calendar. They are here because they are often what people actually want to know.
The table shows the date you reach a range of common ages, from the age of majority to a hundred.
Everything is calculated in your browser, and the date of birth is never sent anywhere.
How the age is worked out
The tool moves the date of birth forward by as many whole months as fit up to and including the chosen day, and counts what is left in days. One month on lands on the same day of the next month, or on the last day of the month if that day does not exist there. The years are the whole months divided by twelve, and the months left over are shown separately.
The figures below the age are based on the number of days between the two dates. Weeks are whole weeks, rounded down, and hours and minutes are the days multiplied by 24 and by 1,440. The tool does not know the time of birth and treats every day as 24 hours, so the clocks going forward or back do not affect the totals. The months in the same box are calendar months and so match the age above them.
Example
Someone born on 17 May 1990 is 36 years, 4 months and 14 days old on 1 October 2026. Step by step: 436 whole months on from the date of birth is 17 September 2026, and from there it is 14 days to 1 October. 436 months is 36 years and 4 months. There are 13,286 days between the dates, which gives 1,898 whole weeks and 318,864 hours. The next birthday is 17 May 2027, 228 days away, when the person turns 37.
When the law says you are a year older
In England and Wales, section 9 of the Family Law Reform Act 1969 says that a person attains an age expressed in years at the commencement of the relevant anniversary of their birth: at the very start of the birthday, not at the hour they were born. The tool counts by date in the same way and shows the new age on the birthday itself.
Scotland has a rule for leap-day births. Section 6 of the Age of Legal Capacity (Scotland) Act 1991 says that for someone born on 29 February the relevant anniversary in a year that is not a leap year is 1 March. The tool uses 28 February instead, for the age, the table, the next birthday and the birthday greeting alike: someone born on 29 February 2008 is shown as turning 18 on 28 February 2026, a day earlier than under the Scottish rule. The 1969 Act has no specific rule for 29 February.