Exact age calculator
Work out your age in years, months, days, weeks and hours from your date of birth.
Calculator inputs
Results
Enter your values and press “Calculate” to see the result.
In short
- What it calculates
- Work out your age in years, months, days, weeks and hours from your date of birth.
- Formula used
Age = complete years + complete months + remaining days- Example
- Born: 1990-03-15
Age calculator
Enter your date of birth and get your exact age in years, months and days, not just completed years.
If you need your age on a specific date (an exam day, a match day), enter it in the second field.
How it works
The calculation respects the real length of every month and leap years. Complete years are counted first, then months, then the leftover days.
The total number of days comes from counting the actual calendar, not from multiplying by 365.
Formula
Age = complete years + complete months + remaining days
Days lived = calendar days between the two dates
Weeks = days lived ÷ 7
Worked example
Born: 1990-03-15
Reference date: 2026-08-21
Age: 36 years, 5 months, 6 days
Days lived: 13,308
Next birthday: in 206 days
Explanation
Legal age counts completed years
Almost everywhere, age for legal purposes means whole years elapsed, not rounded years. Someone aged 17 years and 11 months is 17 in the eyes of the law, with no nuance. That is why this calculator never rounds up: it counts how many birthdays have passed.
Not everyone counts the same way
South Korea used a system for decades in which you were born aged one and gained another year every 1 January, so a baby born in December could be two years old within days. The country officially unified around the international count in 2023, but the custom survives in everyday conversation. China and Vietnam had similar systems.
The dates that hinge on the exact day
Legal majority, retirement age, school year cut-offs and insurance bands are not measured in approximate years: they depend on the specific day. One day's difference can change which school year a child enters or the year someone can retire.
Age on a past or future date
By changing the reference date you can find out how old you were at a particular moment, or how old you will be. It is useful for forms asking for your age 'as at' a given day.
Frequently asked questions
Does it handle leap years correctly?
Yes. The full Gregorian calendar is used, so 29 February days are counted properly.
What if I was born on 29 February?
Your age is calculated the same way. For the next birthday in non-leap years, 1 March is used as the reference.
How old was I on a specific date in the past?
Change the reference date to that day and the result will be the age you were then, in years, months and days.
Why does the law not round age up?
Because rights and obligations are acquired on the exact birthday. Until the day you turn a year older, your legal age remains the previous one.
Need to calculate something else?
These tools are often used alongside this calculator.
Days between dates
Count the days, weeks and months separating any two dates.
Days until
Count the days remaining (or elapsed) between today and the date you choose.
Add days
Get the resulting date after adding a period to a starting date.
Weeks
Count the complete weeks and leftover days separating two dates.
Hours worked
Work out effective working time after breaks, night shifts included.
Working days
Count business days while excluding weekends and public holidays.