Exact age from a date of birth, plus total days lived and the countdown to your next birthday.
Runs in your browser. Nothing is sent, saved, or shared.
Defaults to today. Set a future date to work out how old you will be.
Enter a date of birth. It has to be a real date and cannot be later than the comparison date.
Days and years are straightforward. Months are not, because they run from 28 to 31 days, so "one month later" means different lengths depending on where you start.
The convention used here is calendar-based: count whole years, then whole months, then the days left over. Someone born on 31 January is one month old on 28 February in a non-leap year, because there is no 31st to reach.
About one person in 1,461 is born on 29 February, and in non-leap years there is no exact anniversary. The usual convention treats 1 March as the birthday for legal purposes in most places, though some jurisdictions use 28 February.
This calculator counts total days lived, which sidesteps the question entirely and is the only unambiguous answer available.
Age is a calendar fact, not an instant, so this works in whole days from the date you enter. It does not adjust for the time of day or the time zone you were born in.
For anything legal, that distinction can matter and a document beats a calculator. For everything else it does not.
Day, month, and year. Everything is calculated in your browser and nothing is sent anywhere.
Defaults to today. Set a future date to work out how old you will be then.
Calendar convention: whole years first, then whole months, then remaining days.
Total days lived, and how many days until your next birthday.
Total days, working days, and the same span expressed in weeks and months.
The four percentage questions people actually search for, each with the working shown.
How long your streak is, what rate you are running at, and how much room you have left.
A calculator tells you where you are once. If the thing you actually want is to keep something up, that takes a record rather than a result.
