📅 Date / Age Calculator

Enter your birthday to get your exact age and how many days until your next birthday, or find out how many days are between two dates.

🎂 Age Calculator

Birthday

Days until next birthday
Total days lived

📆 Date Difference Calculator

Start date

End date

📖 How to Use

Age calculator: in the "🎂 Age Calculator" panel, pick your date of birth. The result updates automatically as soon as you enter it — no button to click.
Reading the age result: the big number is your current exact age. The table below shows "Days until next birthday" (it displays "Happy birthday today! 🎉" on the day itself), and "Total days lived" — the total number of days from your birth date to today.
Date difference calculator: in the "📆 Date Difference Calculator" panel below, choose a start date and an end date (both default to today when the page loads). Again, the result updates the moment you change either field.
Reading the difference result: the big number is the number of days between the two dates, and the smaller text below converts that into roughly how many weeks and months for easier reading. If you pick an end date earlier than the start date, the day count still shows as a positive number, with a note that "the end date is before the start date" so you know.

Note: the age shown is your exact age (calculated from your real birth date — you don't turn a year older until the actual day arrives), not any traditional counting system that adds a year at birth. The date-difference math also relies on the browser's built-in date handling, which correctly accounts for leap years (including February 29) and varying month lengths, so you don't need to worry about off-by-one errors.