All Age & Date Calculators
Everything on the site in one place, grouped by category. Search filters across all 161 at once.
Universal Chronology
Age Calculator
Exact chronological age in completed years, calendar months and remaining days.
Exact Age Calculator
A detailed calendar-accurate age result for any reference date.
Age Difference Calculator
The exact calendar gap between two dates of birth.
Age in Days Calculator
Total elapsed days since a date of birth.
Age in Weeks Calculator
Completed weeks and remaining days since birth.
Age in Months Calculator
Age expressed as complete calendar months plus remaining days.
Age in Hours Calculator
A day-resolution estimate of elapsed lifetime hours.
Age in Minutes Calculator
A day-resolution estimate of elapsed lifetime minutes.
Age in Seconds Calculator
A day-resolution estimate of elapsed lifetime seconds.
Age in Specific Units Calculator
The same elapsed age represented across multiple time units.
Date of Birth Calculator
An estimated birth date from age and a selected reference date.
Reverse Age Calculator
A calendar date inferred by subtracting a stated age from a reference date.
Age on a Date Calculator
Chronological age on a past or future date.
How Old Was I Calculator
Age at an earlier event or historical reference date.
How Old Will I Be Calculator
Age on a planned future date.
Birth Year From Age Calculator
A likely birth year and date range from age information.
Decimal Age Calculator
Elapsed age represented as an approximate decimal number of years.
Age at Last Birthday Calculator
Completed whole-year age at the most recent birthday.
Age at Next Birthday Calculator
The next birthday date and age that will be reached.
Age Nearest Birthday Calculator
The nearest annual birthday and its calendar distance.
Age Gap Calculator
The elapsed gap between two personal dates.
Age Range Calculator
Whether a calculated age falls within a custom minimum and maximum range.
Birthday Age Calculator
The upcoming birthday date, weekday and turning age.
Age Timeline Calculator
Age on a past, current or future milestone date with surrounding birthday context.
Korean Age Calculator
Korean age reckoning alongside international age for the same birth date.
East Asian Age Calculator
Traditional East Asian year-count age compared with international age.
Age in Quarters Calculator
Elapsed age expressed in three-month quarters.
Clinical & Academic
Chronological Age Calculator
Chronological age on an assessment date.
Pearson Age Calculator
Calendar age formatting for Pearson-style assessment workflows.
BRIGANCE Age Calculator
Chronological age preparation for BRIGANCE assessment records.
Assessment Age Calculator
Age on a specific testing or evaluation date.
Test Age Calculator
Calendar age at the date a test is administered.
Developmental Age Difference Calculator
The date-based difference between chronological and comparison ages.
Biological & Health
Biological Age Calculator
A non-diagnostic wellness-age estimate based on lifestyle inputs.
Heart Age Calculator
An educational heart-health age index using simple risk-related inputs.
Metabolic Age Calculator
An educational metabolic-age comparison based on basic body and activity inputs.
Fitness Age Calculator
A lifestyle-oriented fitness age estimate for self-reflection.
Body Age Calculator
A general body-age index derived from age and lifestyle markers.
Health Age Calculator
A broad wellness-age estimate that highlights modifiable lifestyle factors.
Brain Age Calculator
A recreational cognitive-lifestyle age estimate rather than a diagnostic result.
Lifestyle Age Calculator
An educational age adjustment based on sleep activity and smoking status.
Pregnancy & Pediatric
Gestational Age Calculator
Gestational age from the first day of the last menstrual period.
Pregnancy Due Date Calculator
An estimated due date from the last menstrual period and cycle length.
Conception Date Calculator
An estimated conception window from LMP or due date.
Pregnancy Week Calculator
Pregnancy week and day on a selected date.
Trimester Calculator
The estimated pregnancy trimester and gestational week.
Fetal Age Calculator
An approximate fetal age derived from gestational age.
Adjusted Age Calculator
Corrected age for a child born before 40 weeks gestation.
Corrected Age Calculator
Chronological age adjusted for weeks of prematurity.
Baby Age in Weeks Calculator
A baby’s chronological age in completed weeks and days.
Baby Age in Months Calculator
A baby’s chronological age in calendar months and days.
Premature Baby Age Calculator
Chronological and corrected age for prematurity-related planning.
Reverse Due Date Calculator
The estimated due date and LMP implied by a current gestational week and day.
IVF Due Date Calculator
An estimated due date calculated from an embryo transfer date and embryo day.
Pregnancy Countdown Calculator
Days remaining until an estimated due date, with trimester context.
Birthday & Milestones
Birthday Countdown Calculator
Time remaining until the next birthday.
Next Birthday Calculator
The next birthday date weekday and turning age.
Golden Birthday Calculator
The birthday when age matches the day number of birth.
10,000 Days Old Calculator
The calendar date on which 10,000 elapsed days are reached.
Billion Seconds Calculator
The date corresponding to one billion elapsed seconds.
Milestone Birthday Calculator
The date of a custom milestone birthday.
Half Birthday Calculator
The approximate calendar midpoint between annual birthdays.
Birthday Weekday Calculator
The weekday of a selected birthday year.
Birthday Number Calculator
A recreational numerology number derived from a birth date.
Custom Day Milestone Calculator
The date reached after a user-selected number of elapsed days.
Leap-Day Birthday Timeline
Upcoming February 29 birthdays and non-leap-year anniversary context.
Custom Milestone Timeline
Dates for several upcoming custom year milestones.
1,000 Days Old Calculator
The calendar date on which a person completes 1,000 days of life.
20,000 Days Old Calculator
The calendar date on which a person completes 20,000 days of life.
Million Minutes Calculator
The date on which one million minutes of life have elapsed.
Next Milestone Birthday Calculator
The next four milestone birthdays at a chosen interval.
Quarter Birthday Calculator
The three-month quarter birthday date measured from a birth date.
Professional & Education
Age at Event Calculator
Age on an event date such as graduation employment or another milestone.
School Starting Age Calculator
Age on a chosen school-entry date compared with a custom minimum age.
Kindergarten Eligibility Calculator
Age on a selected kindergarten cutoff date under a user-entered rule.
Academic Year Age Calculator
Student age on a chosen academic-year reference date.
School Grade Age Calculator
Age on a school cutoff date for a custom grade-entry rule.
Exam Age Calculator
Age on an exam date compared with a user-entered age requirement.
Sports Eligibility Age Calculator
Age on a sports cutoff date compared with a custom age range.
Graduation Age Calculator
Age on a graduation or completion date.
Driving Age Date Calculator
The date a selected driving-age threshold is reached.
Voting Age Date Calculator
The date a selected voting-age threshold is reached.
Work Anniversary Countdown
The next employment anniversary and completed service duration.
Term Date Planner
The next scheduled date in a repeating academic or term calendar.
Semester Length Calculator
The length of a semester or term in weeks, days and calendar months.
Age at Marriage Calculator
Exact age on a wedding or civil partnership date.
Anniversary Milestone Calculator
The date of a chosen anniversary milestone and the countdown to it.
Finance & Professional
Retirement Age Calculator
A chosen retirement-age milestone date.
RMD Age Calculator
A planning date for a user-entered required-distribution age.
Years of Service Calculator
Exact employment service duration between two dates.
Work Anniversary Calculator
The next employment anniversary and completed service years.
Pension Age Date Calculator
The date a chosen pension-planning age is reached.
Early Retirement Date Calculator
The date a selected early-retirement target age is reached.
Employment Duration Calculator
Calendar duration of employment or service.
Service Milestone Calculator
A future employment milestone based on a chosen service year.
Career Length Calculator
Elapsed career duration between start and reference dates.
Working Days in Month Calculator
The number of weekdays in a selected calendar month.
Notice Period End Date Calculator
The end date of a notice period counted in working days.
Probation Period End Calculator
The calendar end date of a probation period expressed in months.
Long Service Leave Calculator
Continuous service duration used when checking long-service entitlements.
Nature & Life Cycles
Dog Age Calculator
Dog age expressed as an approximate human-age equivalent.
Cat Age Calculator
Cat age expressed as an approximate human-age equivalent.
Tree Age Calculator
An estimated tree age from trunk circumference and growth factor.
Planetary Age Calculator
An Earth age converted to approximate ages on other planets.
Horse Age Calculator
Horse age expressed as a simple human-age comparison.
Rabbit Age Calculator
Rabbit age expressed as a simple human-age comparison.
Bird Age Calculator
Bird age expressed as a broad educational human-age comparison.
Turtle Age Calculator
Turtle age represented using a simplified life-stage comparison.
Fish Age Calculator
An approximate human-equivalent comparison for a pet fish's age.
Life Statistics
Heartbeats Lived Calculator
Estimated lifetime heartbeats from age interval and average beats per minute.
Breaths Lived Calculator
Estimated lifetime breaths from age interval and average breaths per minute.
Sleep Time Lived Calculator
Estimated lifetime time spent sleeping from average hours per day.
Life Progress Calculator
The percentage of a user-selected lifespan target already elapsed.
Sleep Debt Calculator
Accumulated sleep shortfall over a chosen period against a nightly sleep target.
Screen Time Lived Calculator
An estimate of total time spent on screens across a lifetime at a stated daily average.
Culture & Birth Profile
Zodiac Sign Calculator
Western zodiac sign associated with a birth month and day.
Chinese Zodiac Calculator
Chinese zodiac animal associated with a birth year.
Birthstone Calculator
Traditional birthstone associated with a birth month.
Birth Flower Calculator
Traditional birth flower associated with a birth month.
Birth Color Calculator
A recreational color association based on birth month.
Birth Season Calculator
Meteorological season associated with a birth month in the Northern Hemisphere.
Birth Month Facts Calculator
A compact recreational profile based on birth month.
Life Path Number Calculator
A recreational numerology life-path number from a birth date.
Birthday Moon Phase Estimator
An approximate lunar phase index for a birth date.
Day of Week Born Calculator
Weekday on which a person was born.
Generation Calculator
A broad generational label based on birth year.
Lunar Birthday Calculator
The approximate moon phase on a birth date and its position in the lunar cycle.
Date Lab
Days Between Dates Calculator
Elapsed calendar days between two dates.
Date Difference Calculator
Calendar difference in years months days and total days.
Time Between Dates Calculator
Calendar duration between two selected dates.
Add Days to Date Calculator
A future or past date after adding calendar days.
Subtract Days From Date Calculator
A date found by subtracting calendar days.
Add Weeks to Date Calculator
A date after adding complete seven-day weeks.
Subtract Weeks From Date Calculator
A date found by subtracting complete weeks.
Add Months to Date Calculator
A calendar date shifted forward by complete months.
Subtract Months From Date Calculator
A calendar date shifted backward by complete months.
Add Years to Date Calculator
A calendar date shifted forward by complete years.
Subtract Years From Date Calculator
A calendar date shifted backward by complete years.
Business Days Calculator
Weekdays between two dates with weekends excluded.
Workdays Between Dates Calculator
Monday-to-Friday workdays across a date interval.
Week Number Calculator
ISO week number for a selected calendar date.
Day of Year Calculator
Ordinal day number within the selected year.
Days Left in Year Calculator
Remaining calendar days before the end of the year.
Leap Year Calculator
Whether a selected year follows the Gregorian leap-year rule.
Weekday Calculator
Day of the week for any valid calendar date.
Months Between Dates Calculator
Complete calendar months and residual days between dates.
Years Between Dates Calculator
Complete calendar years plus remaining months and days.
Date Midpoint Calculator
The exact midpoint date between two calendar dates.
Inclusive Date Count Calculator
The number of calendar days with explicit start- and end-date inclusion.
Business Date Shift Calculator
A date moved forward or backward by weekdays.
Recurring Date Calculator
The next occurrence in a repeating day, week, month or year schedule.
ISO Week to Date Converter
The calendar dates covered by a given ISO-8601 week number and week-year.
Fiscal Quarter Calculator
The fiscal quarter, quarter start and quarter end for any date and fiscal-year start month.
Quarter End Date Calculator
The last day of the calendar or fiscal quarter containing a chosen date.
Working Hours Between Dates Calculator
Scheduled working hours between two dates using a chosen working day length.
Time Zone Date Difference Calculator
The real elapsed interval between two local date-times in different UTC offsets.
Countdown to Any Date Calculator
Days, weeks and weekdays remaining until any chosen target date.
Days Until Christmas Calculator
The number of days remaining until the next 25 December.
Days Until New Year Calculator
The number of days remaining until the next 1 January.
Weeks Between Dates Calculator
Complete weeks and remaining days between two calendar dates.
Public Holidays Between Dates
The public holidays falling between two dates in a chosen jurisdiction, including substitute days.