Age Calculator (Years, Months and Days)
This age calculator gives your exact age from your date of birth in years, months and days. Someone born on 20 May 1990 was 36 years, 5 months and 16 days old on 5 November 2026, which is 13,318 days. It also counts down to your next birthday and tells you which day of the week you were born.
- Days in a year365 (366 in a leap year)
- Leap yearsevery 4 years, with exceptions
- Age at a set dateschool, pension, licence
Updated November 2026 · Counts leap years automatically
Calculate your exact age
Your result
Fill in the details, then press Calculate to see your result with the working shown.
You changed your details. Press Calculate to update the result.
How to calculate age from date of birth
To work out an exact age, subtract the birth year from the current year, then check whether the birthday has happened yet this year. If it has not, take one off. For the months and days, count the whole months since the last birthday, then the days left over.
Example: born 20 May 1990, age on 5 November 2026. The 2026 birthday has passed, so the age is 2026 − 1990 = 36 years. From 20 May to 20 October is 5 months, and from 20 October to 5 November is 16 days, giving 36 years, 5 months and 16 days.
How many days old am I?
The calculator counts every calendar day between the two dates, including the extra day in each leap year. A year has 365 days, or 366 in a leap year. Leap years fall every four years, except century years that are not divisible by 400, so 2000 was a leap year but 1900 was not.
| Age | Approximate days alive | Approximate weeks |
|---|---|---|
| 1 year | 365 | 52 |
| 10 years | 3,652 – 3,653 | 521 |
| 18 years | 6,574 – 6,575 | 939 |
| 30 years | 10,957 – 10,958 | 1,565 |
| 50 years | 18,262 – 18,263 | 2,608 |
Age on a particular date
Use the second date box to find an age on a set day, for example on 31 August for the school year, on the day of an exam or on the date a policy starts. Many UK rules depend on age on a specific day:
- School year groups in England and Wales are set by age on 31 August; in Scotland the cut-off is usually the end of February.
- You can apply for a provisional driving licence at 15 years and 9 months and drive a car at 17.
- State Pension age is currently 66 and is rising to 67 between 2026 and 2028.
Leap year birthdays
If you were born on 29 February, you have a calendar birthday only once every four years. In the UK you are treated as reaching a new age on 1 March in non-leap years, which matters for things like turning 18. The calculator shows 1 March as your next birthday in those years.
Frequently asked questions
How do I work out my exact age?
Subtract your birth year from the current year, take one off if your birthday has not happened yet this year, then count the months and days since your last birthday.
How many days old am I if I am 30?
Roughly 10,957 days, depending on how many leap years you have lived through and how far you are past your 30th birthday.
What day of the week was I born?
Enter your date of birth and the calculator shows the day, for example 20 May 1990 was a Sunday.
When is a leap-year baby legally a year older?
In the UK, someone born on 29 February is treated as reaching their new age on 1 March in years that are not leap years.
Does the age calculator count leap years?
Yes. It counts real calendar days between the two dates, so every 29 February in between is included.
Sources and method
We use official UK guidance and recognised formulas, and test each calculator against worked examples. Results are estimates to help you plan, not professional advice. See how we work.