Exact age calculator
Enter a date of birth and we work out the exact age in years, months and days, plus how long is left until the next birthday.
Your figures
Result
- Full years
- 36
- Days to the next birthday
- 278
- Born on a
- Friday
- Months lived
- 434
- Days lived
- 13,236
- Weeks lived
- 1,890.9
What we assume
- Age is counted in full years: you do not turn a year older until the exact date arrives.
- Months are calendar months, not blocks of 30 days.
- For anyone born on 29 February, 28 February is treated as the birthday in non-leap years.
How it is calculated
The age is worked out by subtracting years first, then months, then days, borrowing from the real previous month when needed. It is the same rule any official document uses: you are 36 right up to the exact day you turn 37.
You can change the reference date to answer questions like "how old will I be when term starts?" or "how old was I on that date?".
An example
Someone born on 15 June 1990 was, on 20 April 2026, 35 years, 10 months and 5 days old. They were born on a Friday.
Frequently asked questions
How is the age counted for someone born on 29 February?
In non-leap years we treat 28 February as the birthday. It is the same clamping rule we apply when adding months everywhere on the site, so that the age and the birthday date never contradict each other. Some argue for 1 March: the difference is a single day and only on that one date.
Can I find out how old I will be on a future date?
Yes. Change the "work out the age as of" field to whatever date you want.
Why are months not 30 days long?
Because age is expressed in calendar months. From 15 January to 15 February is one month, whether February has 28 days or 29.
Keep calculating
All tools →- Days between two dates calculator Enter two dates and we tell you how many days lie between them, broken down into weeks, spare days and hours.
- Difference between two dates in years, months and days Rather than counting loose days, this gives you the difference the way you would say it out loud: "2 years, 3 months and 5 days".
- Working days between two dates Count only the real working days between two dates: weekends come out, and public holidays too if you want them to.
- Add or subtract days from a date Give me a date and how many days to add or subtract. Count every day, or working days only.
- Work hours calculator With your start time, finish time and break, we work out the effective day and what it adds up to over a week, a month and a year.
- Week number of the year Which week of the year a date falls in, under ISO 8601, which is the standard businesses use and does not always match what you would guess.
Updated on 2026-08-26. Calculations run in your browser; nothing you type is sent to a server.