Birthday Calculator
Enter your birthday to find your exact age, days until your next birthday, total days you have lived, and the day of the week you were born.
What Does This Tool Do?
Enter your date of birth to get your exact age, how many days until your next birthday, total days you have been alive, and the day of the week you were born.
Key Features
Exact Age
Years, months and total days.
Next Birthday
Countdown in days to your next birthday.
Day of Birth
The day of the week you were born.
Days Lived
Total number of days you have been alive.
How to Use
- Select your date of birth from the date picker.
- Click Calculate.
- View all birthday facts instantly.
Frequently Asked Questions
How is exact age calculated?▾
Age = current year − birth year, then adjusted back by 1 if your birthday has not yet occurred this calendar year.
What if today is my birthday?▾
The calculator will show 0 days until birthday and display a birthday cake emoji 🎂.
Is the day of birth accurate for old dates?▾
JavaScript's Date uses the Gregorian calendar back to 1970 exactly and extrapolates further back — accuracy decreases for dates before the Gregorian reform in 1582.