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Age Calculator
Work out an exact age in years, months and days.
Age Calculator tool
Defaults to today. Change it to measure to any other date.
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Years
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Months
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Days
The same span in other units
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Total months
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Total weeks
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Total days
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Total hours
Details
About the Age Calculator
Age Calculator turns a date of birth into an exact age. The headline result is given the way people say it, as years, months and days, counted properly so that month lengths and leap years are respected rather than approximated.
Underneath, the same span is expressed as a single total in months, weeks, days and hours. These totals answer different questions: total days is useful for eligibility rules and record keeping, total weeks for pregnancy and project timelines, and total months for anything measured in monthly instalments.
You can calculate against today or against any other date, which turns the tool into a general date-difference calculator. That covers questions such as how old someone will be at a future event, or how long ago something happened. The next birthday and the weekday of the birth date are shown as well.
How to use the Age Calculator
- Enter the date of birthUse the date field, or type the date directly.
- Choose the date to measure toToday is used by default; change it to measure to any other date.
- Read the exact ageYears, months and days appear together, with totals underneath.
- Check the next birthdayThe countdown shows how many days remain.
Features
- Exact age in years, months and days
- Totals in months, weeks, days and hours
- Measure to today or to any chosen date
- Days remaining until the next birthday
- Day of the week the birth date fell on
- Correct handling of leap years and uneven month lengths
- Clear message if the dates are the wrong way round
Who uses this tool
The age calculator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:
- Checking an exact age for a form or an application
- Confirming eligibility that depends on an age threshold
- Measuring the gap between any two dates
- Finding how many days remain until a birthday
- Working out an age as it will be on a future date
Frequently asked questions
How are months counted when they have different lengths?
The calculation walks forward whole months from the birth date, then counts the remaining days. That matches how people describe age in conversation and avoids the distortion you get from dividing total days by an average month length.
Does it handle leap years?
Yes. Leap days are included in every total, and the calculation uses real calendar dates rather than a fixed 365-day year.
What happens to a 29 February birthday?
In a non-leap year the birthday is treated as falling on 1 March for the purpose of the countdown. Conventions differ by country for legal purposes, so check local rules if the distinction matters.
Can I measure a gap between two dates that is not an age?
Yes. Put the earlier date in the first field and the later date in the second, and the result is simply the span between them.
Why does the hours total look approximate?
Because the calculation works in whole days and multiplies by 24. Daylight saving changes make some days 23 or 25 hours long, so the hours figure is close rather than exact to the minute.
Is the date I enter stored anywhere?
No. The calculation happens in your browser and nothing is saved or transmitted.
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