Age Calculator
Find your exact age in years, months and days, and the countdown to your next birthday.
Results update as you type.
About this calculator
An age calculator finds the exact time between your date of birth and today — in years, months and days — and counts down the days to your next birthday. It counts complete years first, then the whole months left over, then the remaining days, correctly handling months of different lengths and leap years. It also totals your life in months, weeks, days and hours.
For example, someone born on 15 March 1990, measured on 8 July 2026, is 36 years, 3 months and 23 days old — roughly 435 months, about 1,890 weeks or over 13,200 days lived. The next-birthday line shows how many days remain until the date rolls around again.
Set an "age at date" under advanced options to find how old you were, or will be, on any past or future day — handy for anniversaries, eligibility cut-offs, retirement dates or working out someone’s age from a document. Leave it blank to calculate age as of today.
Frequently asked questions
How is exact age calculated?
It counts full years from your birth date to the target date, then the remaining whole months, then the leftover days — accounting for different month lengths and leap years.
Can I calculate age on a future or past date?
Yes. Set "Age at date" under advanced options to any date to see how old you were or will be then.
How many days old am I?
The calculator divides the exact time since your birth date by one day and shows the total, along with your age in hours, weeks and months. It counts every day including leap days, so the figure is exact.
How does it handle leap years?
It works with real calendar dates, so leap days are counted automatically in the day, week and hour totals. The years-months-days breakdown also adjusts for the actual length of each month between the two dates.
Why is my age in months not just years times twelve?
The exact age keeps the leftover months and days separately, so someone 36 years and 3 months old is 435 total months — the extra three months on top of 36 × 12. The "total months" result gives that combined figure.
Can I use it to find someone else’s age?
Yes. Enter their date of birth instead of yours. Because you can also set the "age at date", you can find how old anyone was on a specific day, such as at an event or on a legal deadline.
Results are estimates for general guidance only, not financial, medical or tax advice.