Age in Months
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Complete calendar months plus remaining days.
Age Calculator
Calculate your exact age in years, months, weeks, and days. Find your age on any date, discover your next birthday, and explore detailed age information instantly.
Enter Your Dates
Enter your date of birth to calculate your age.
Choose today, a past date, or a future date.
Enter your date of birth to calculate your exact age.
Your Age
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Age in Weeks
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Complete elapsed weeks plus remaining days.
Age in Days
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Exact elapsed calendar days.
Age in Years
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Completed calendar years.
Next Birthday
Next Birthday
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Days Until Next Birthday
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Age You Will Turn
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Birthday Weekday
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Date & Calendar Information
Date of Birth
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Born On
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Age On
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Calculation Type
Exact calendar age
Total Age Statistics
Total Years
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Total Months
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Total Weeks
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Total Days
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Calendar age uses years, months, and days because calendar months have different lengths. Total days are calculated separately using exact calendar-day differences.
Your dates are processed directly in your browser. No personal date information is sent to our server.
What Is an Age Calculator?
An age calculator is an online date-of-birth calculator that determines how old a person is on a selected date. Instead of giving only a number of years, an exact age calculator can show the result in years, months, and days and can also provide total elapsed months, weeks, and days.
NameUpWeb's Age Calculator lets you calculate your age today or select a specific past or future date. It also provides your birth weekday, next birthday, birthday countdown, and the age you will turn.
How Does an Age Calculator Work?
The calculator compares your date of birth with the date you choose in the "Calculate Age On" field. The exact result is based on calendar arithmetic rather than dividing the number of elapsed days by 365 or 365.25.
First, completed calendar years are determined. The remaining period is then calculated in calendar months and days. Total elapsed days are calculated separately so that weeks and days can be displayed without changing the meaning of the exact calendar age.
How to Calculate Your Age
1
Enter your date of birth.
2
Select the date you want to calculate your age on.
3
Click Calculate Age.
4
Review your exact age in years, months, and days.
5
Explore total months, weeks, days, and your next birthday.
Age in Years, Months, Weeks and Days
Your primary result is shown as years, months, and days because this is the natural calendar representation of age. For example, someone may be 25 years, 4 months, and 12 days old on a particular date.
The calculator also provides age in months, age in weeks, and age in days. Total months represent complete calendar months plus the remaining days. Total weeks represent complete elapsed seven-day periods plus remaining days. Total days represent the exact number of calendar days between the two dates.
How Exact Age Is Calculated
Exact calendar age is not calculated by simply dividing total days by 365. Different months contain different numbers of days, and leap years add another calendar-day difference.
The calculator determines completed calendar years, then calculates the remaining calendar months and days. Day differences are handled separately using date-only UTC calculations to avoid daylight-saving-time changes affecting the result.
How to Calculate Age on a Specific Date
You can use the "Calculate Age On" field to find your age on a particular date. This can be useful for checking an age at a historical date, calculating an age on a future date, or determining how old someone was on an important event date.
For example, if the date of birth is January 15, 2000 and the selected date is January 15, 2025, the exact age is 25 years, 0 months, and 0 days. If the selected date is January 20, 2025, the result is 25 years, 0 months, and 5 days.
Why Use an Online Age Calculator?
Manually calculating an exact age can become complicated around month ends, leap years, and February 29 birthdays. An online age calculator performs those calendar calculations consistently and presents the result in an easy-to-read format.
It is also useful when you need more than a basic age in years. The detailed results can show total days, total weeks, total months, birth weekday, and the date and countdown for the next birthday.
Leap Years and February 29 Birthdays
A Gregorian calendar leap year is divisible by 4, except years divisible by 100 are not leap years unless they are also divisible by 400. Therefore, 2000 and 2024 are leap years, while 2100 is not.
For a person born on February 29, this calculator uses February 28 as the birthday convention in non-leap years. This provides a consistent way to calculate birthdays when February 29 does not occur in the selected year.
Age Calculator Examples
Example 1
Date of Birth: January 15, 2000
Age At: January 15, 2025
Result: 25 Years, 0 Months, 0 Days
Example 2
Date of Birth: January 15, 2000
Age At: January 20, 2025
Result: 25 Years, 0 Months, 5 Days
Example 3
Date of Birth: February 29, 2000
Age At: February 28, 2025
Result: Uses February 28 as the non-leap-year birthday convention.
Frequently Asked Questions
An age calculator compares your date of birth with a selected calculation date and uses calendar arithmetic to determine completed years, months, and remaining days.
Yes. Enter your date of birth and choose any valid future date in the Calculate Age On field. The calculator will determine your age on that date.
Yes. You can select a date after your birth date in the past. The calculator does not require the calculation date to be today or in the future.
Yes. The calculator shows complete calendar months together with any remaining days. It also provides a total-month statistic based on the calendar age.
Yes. Total elapsed days are divided into complete seven-day weeks and remaining days, so the result can be shown as weeks and days.
Yes. The Age in Days result gives the exact number of elapsed calendar days between the date of birth and the selected calculation date.
Yes. Gregorian leap-year rules are used, including the special rules for century years and years divisible by 400.
For February 29 birthdays, February 28 is used as the birthday convention in non-leap years. In leap years, February 29 is used normally.
The primary years, months, and days result uses exact calendar arithmetic. Total days are calculated separately as an exact calendar-day difference rather than an approximation based on 365 days per year.
No. The calculations are performed directly in your browser. The tool does not need to send your dates to a server for the calculation.
Yes. You can use this online Age Calculator to calculate exact calendar age, total days, weeks, months, and birthday information directly in your browser.