Every calculation, precisely dated.
One instrument, tuned for exact answers: age in years, months and days; birthday countdowns; pregnancy dating; pet years; eligibility windows; and more — all calculated instantly in your browser.
Browse every calculator
Core Age Tools
Birthday Tools
Time-Based Age
Date Difference Tools
Pregnancy & Baby
School & Career
Health & Science
Pet Age
Fun Calculators
Why AgeCalculator.ai
Every tool on this site shares one calendar-accurate engine: it works in real calendar days, correctly handling leap years and variable month lengths, so results match what you'd get counting by hand — just instantly.
Nothing you enter is uploaded anywhere. Every calculation runs client-side, in your own browser, and nothing is stored once you close the tab.
How the tools are organised
Core & time-based age
Exact age, age in days/weeks/months/years, and everything measured from a single date of birth.
Dates, birthdays & eligibility
Gaps between two dates, countdowns to the next birthday, and age-based eligibility windows for school, work, and government schemes.
Life stages & species
Pregnancy dating, baby age tracking, pet-to-human year conversion, and general wellness age estimates.