Age calculator by date of birth
Your date of birth is all this calculator needs. Enter it below and you get your exact age in years, months and days — not a rounded year, but the precise figure used on forms, applications and official records — plus your total days lived and your next birthday.
🔒 100% private: the dates you enter never leave your device. All calculations happen in your browser — nothing is uploaded, stored, or seen by us.
How the age by date of birth calculation works
The calculator counts complete years from your birth date to today, then complete months since your last birthday, then the remaining days — borrowing days from the correct month when needed and counting every 29 February in between. That is why the result is exact, where a shortcut like "days ÷ 365" drifts by several days over a lifetime. Our guide to how to calculate age walks through the method step by step.
One calculator, every way people ask for it
People phrase the same question many ways — an age calculator of dob, an age calculator by dob, or an age calculator from dob — and they all mean this page: give your date of birth, get your exact age. The "Age at date" field covers the other common variant: your age by year, or your age on any specific date. Set it to a cutoff date — a school admission date, a job application deadline, 1 January of a given year — and the result is your age on that day instead of today.
What you get besides your age
- Total days lived — your age expressed as a single day count, leap days included.
- Total months, weeks and hours — the same age in the units forms and milestones sometimes ask for.
- Your next birthday — the date, the weekday it falls on, how many days away it is, and the age you will turn.
Frequently asked questions
How do I calculate my age by date of birth?
Enter your date of birth in the calculator above and press Calculate age. You get your exact age in years, months and days, counted on the real calendar including leap years.
What is an age calculator of dob?
It is the same thing as this page: a calculator that takes your date of birth (DOB) and works out your exact age. People also call it an age calculator by dob or from dob — all three phrases mean the same tool.
Can I find my age by year, or my age on a specific date?
Yes. Set the "Age at date" field to that date — for example 1 January 2030, or a school or job cutoff date — and the calculator shows your age on that day instead of today.
How many days old am I?
The results show your total days lived, along with total months, total weeks and total hours. Leap days are counted automatically because the calculation uses real calendar dates.
Is my date of birth private?
Completely. The calculator runs in your browser; the dates you enter are never uploaded or stored anywhere.
Looking for the general calculator? It is on the AgeCalc home page →