Age Calculator 🔒 Your data never leaves your browser.
Calculate exact age in years, months and days between two dates.
About this tool
This age calculator works out an exact calendar-aware breakdown between two dates — years, months and days — the same way people count age by hand, rather than a raw day-count divided by 365.25. Pick a date of birth and, optionally, a different reference date to see how old someone was (or will be) on any given day.
Alongside the years/months/days breakdown you get the totals: how many whole days and weeks that span covers, plus a countdown to the next birthday. Everything runs locally in your browser — no dates are ever sent anywhere.
Frequently asked questions
Why does the month/day count look different from a simple subtraction?
This calculator does calendar-aware date math, borrowing from the previous month when the "day" component would go negative (the same way you'd count age by hand) — so it correctly handles different month lengths and leap years, rather than just subtracting the raw numbers, which can give a wrong or even negative day count around month boundaries.