Age & Date Difference Calculator
Calculate your exact age in years, months and days, or find the time between two dates, including total days, weeks and hours. Free, accurate and private.
Runs in your browser. Nothing is uploaded.
Result
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- Total months
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- Total weeks
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- Total days
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- Total hours
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About this tool
This calculator has two modes. In “Age” mode, enter a date of birth and it tells you exactly how old you are in years, months and days, which weekday you were born on and how many days remain until your next birthday. In “Date difference” mode, enter any two dates to see the time between them.
Both modes also give you the total number of months, weeks, days and hours. The calculation follows the real calendar, including leap years and months of different lengths, so results are exact. If the end of a month is shorter than the start day, as with 31 January plus one month, the calculator uses the last day of that month. Dates never leave your browser.
How to use it
- Choose “Age” to calculate how old someone is, or “Date difference” to compare two dates.
- Enter the dates using the date pickers or by typing them. In Age mode, the “age at” date is set to today and you can change it.
- Read the headline result in years, months and days, and the totals underneath.
- In Age mode, check the line below the result for the weekday of birth and the days until the next birthday.
Frequently asked questions
How is my age calculated?
The calculator counts the full years, then the remaining full months, then the remaining days between your birth date and the chosen date, following the real calendar.
How are leap years handled?
Leap years are built in, including the rule that century years like 1900 are not leap years unless divisible by 400. For a 29 February birthday, the birthday is treated as 28 February in common years.
Does the calculator count the end date?
The difference counts the days from the start date up to the end date, so the same date twice is zero days and consecutive days are one day apart.
Can I find the number of days between two dates?
Yes. Switch to “Date difference”, enter both dates and read “Total days”. It also shows total weeks, months and hours.
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