Exact to the day
Calendar-aware maths that handles leap years and months of different lengths correctly.
Free • Private • Instant
Age & Date Difference Calculator
Find your exact age in years, months and days, measure the time between any two dates, or count down the days to the moments that matter.
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Built for accuracy
Every unit you need
Years, months, weeks, days, hours and minutes, plus business days between dates.
Live countdown
Watch the seconds tick down to any date, or see how long ago something happened.
Private by design
Everything runs in your browser. No sign-up, no tracking, no data leaves your device.
Frequently asked questions
How is exact age calculated?
We count whole years from the birth date, then whole months, then the remaining days. When the day of the month is earlier than the birth day, we borrow the actual length of the previous month.
Is my data stored anywhere?
No. All calculations happen locally in your browser and nothing you enter is sent to a server.
What if I was born on February 29?
In non-leap years your birthday is counted as February 28.
What does "include end date" do?
It adds one day to the result, which is useful for counting both the first and last day, such as a hotel stay or project duration.
Which time zone is used?
Dates use your device's local time zone. The countdown uses the time you pick in the same zone.