What it is
Age Calculator is a free online tool that calculates your exact age in years, months and days from your date of birth and a reference date. It also shows total months, weeks, days, hours, minutes and seconds lived, plus your next birthday countdown, zodiac sign and the weekday you were born.
Why it was created
Many calculators approximate age by dividing days by 365. That's quick but wrong for calendar use. We built this one to be calendar-accurate: real month lengths, leap years, February 29 handling and month-end correctness — while staying extremely simple to use.
Focus on accuracy
- Years → months → days borrowing with correct days per month
- Leap-year rule: divisible by 4, not by 100 unless also by 400
- February 29 birthdays treated as February 28 in non-leap years
- UTC midnight math to avoid timezone drift
Focus on simplicity
No sign-up, no clutter. Enter two dates, press Calculate Age, see results instantly. It works with keyboard, mouse and touch, and the reference date defaults to today without hard-coding.
Focus on accessibility
Semantic HTML, proper labels, visible focus, keyboard support, good color contrast, logical heading order and reduced-motion respect throughout. The layout is mobile-first and never overflows on small screens.
Focus on speed
Static Astro pages, minimal JavaScript, no backend for calculations, lightweight CSS via Tailwind. The page feels instant even on slower connections.
Privacy-conscious
Dates are processed locally in your browser. We don't store them on a server. If analytics or ads are added later, the privacy policy will be updated to reflect that.