Time & Date
Age Calculator
Find exact age or the time between any two dates, with calendar years/months/days, total days and weeks, weekdays, and next birthday countdown.
Age / difference
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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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Student quick launch
Grade planning, algebra checks, and formulas students reach for most.
Study path
Use this calculator with
Follow these when you want the formula behind the answer, a short lesson, or nearby tools in the same topic.
What this age calculator can solve
| Mode | Use it when | Output |
|---|---|---|
| Exact age | You know a birth date and as-of date | Age, totals, weekday born, and next birthday countdown |
| Date difference | You need the distance between any two dates | Calendar difference plus total days, weeks, months, and hours |
How exact age is calculated
The calculator counts full calendar years first, then full months, then remaining days. This is why exact age does not equal total days divided by 365.
Why totals do not always match simple multiplication
Months have different lengths and leap years add days. Total days is the precise day count; total months is the number of full calendar months plus full years converted to months.
Worked examples
Born Jan. 1, 2000 to May 8, 2026
Exact age with totals
Age / difference
26 yr 4 mo 7 d
Leap day birthday
Feb. 29, 2000 to Feb. 28, 2026
Age / difference
25 yr 11 mo 30 d
Project date range
Jan. 1, 2020 to May 8, 2026
Age / difference
6 yr 4 mo 7 d
Frequently asked questions
How does this handle Feb. 29 birthdays?+
For next-birthday countdowns in non-leap years, Feb. 29 rolls to Feb. 28. The exact date difference still counts actual calendar days.
Can I calculate age in the future?+
Yes. Set the as-of date to a future date to see what the age will be then.
Why does total months not equal days divided by 30?+
Because calendar months are not all 30 days. Total months counts full calendar months after full years are accounted for.
Does this use time zones?+
No. It treats inputs as local dates, which avoids time-zone shifts for birthday and date-difference calculations.
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Last updated: May 8, 2026