Age Calculator
Your exact age in years, months, days β plus the next birthday.
About the age calculator
Enter a date of birth and get an exact age in years, months and days, worked out with calendar-aware arithmetic rather than a flat 365-day year β so leap years and short months land correctly. Alongside it: total age in months, weeks, days, hours and minutes, and a countdown to the next birthday with the age that will be reached.
You can also set the "Age at" field to any date, which answers questions like how old someone was on a particular day, or how old they will be at a future event.
How age is actually calculated
The naive approach β dividing total days by 365.25 β drifts, because months are uneven and leap years are not evenly spaced. This calculator counts whole months first, steps the birth date forward by that many months while clamping to the end of short months, then measures the remaining days from there.
That clamping is what makes end-of-month cases behave. Someone born on 31 January is one month old on 28 February in a common year, and 31 March plus one month is 30 April, not 1 May. It is also the answer to the leap-day question: a person born on 29 February turns a year older on 28 February in common years under most legal systems, which is what this calculator reports.
Frequently asked questions
How do I calculate my exact age?
Enter your date of birth above. The result shows your age in years, months and days, using calendar arithmetic rather than a fixed 365-day year, so leap years are handled correctly.
How old am I in days?
The statistics row shows your total age in months, weeks, days, hours and minutes. The day count is exact, including every leap day since you were born.
How does the calculator handle a 29 February birthday?
Someone born on 29 February is treated as gaining a year on 28 February in common years, which matches how most legal and administrative systems handle it. In leap years the birthday falls on 29 February as normal.
Can I find out how old I was on a specific date?
Yes. Change the "Age at" field from today to any date, past or future, and the calculation runs against that date instead.
When is my next birthday?
The card underneath shows the exact date, the day of the week it falls on, how many days away it is, and the age you will turn.