Forms ask for your age in years, friends ask "how old exactly?", and every so often you want to know how many days you have been alive. Enter a birth date and this calculator answers all of it — down to the day — with a countdown to your next birthday.
How age is calculated
This tool uses the running-age convention used almost everywhere: you are 0 years old at birth and gain a year on each birthday. The months and days are counted on the calendar, borrowing from the previous month when the day of month overflows (so one month after Jan 31 is Feb 28 in a common year).
Star signs and the Chinese zodiac
Western star signs are divided by birth month and day — Aries (Mar 21–Apr 19), Taurus (Apr 20–May 20) and so on. The Chinese zodiac assigns an animal to each lunar year: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig. This tool estimates the animal by calendar year; if you were born in January or February, before the Lunar New Year, your animal is the previous one.