Birthday Calculator
Birthday Calculator: Countdown to Your Next Birthday and Your Exact Age
A birthday calculator shows how long you have until your next birthday and how long you have been alive. Enter your date of birth, and the time of birth if you know it, and this free tool gives you a live countdown in days, hours, minutes and seconds, the weekday of your next birthday, and your exact age in years, months and days. It also counts the months, days, hours and seconds you have lived, and the seconds update while the page stays open. A slider lets you list your next birthdays, up to ten, with the weekday each one falls on.
Quick answer: your age is the number of full years since your birth date, plus the extra months and days. Your next birthday is the next time your birth month and day come around. The seconds are the total time since your birth divided into seconds, so a person who is 30 years old has lived about 946,000,000 seconds.
How the Birthday Calculator Works
The calculator compares your birth date with the current date and time on your device. It finds the next date that matches your birth month and day, and counts down the time left in seconds.
If you do not enter a time of birth, the calculator uses midnight at the start of your birth date. A leap day birthday on February 29 is counted on March 1 in years without a leap day.
Examples
The table shows ages and next birthdays as they would appear on October 6, 2026.
| Born on | Age on October 6, 2026 | Next birthday | Weekday |
|---|---|---|---|
| March 15, 1995 | 31 years, 6 months, 21 days | March 15, 2027 | Monday |
| October 6, 2000 | 26 years, 0 months, 0 days (today) | October 6, 2027 | Wednesday |
| December 25, 2010 | 15 years, 9 months, 11 days | December 25, 2026 | Friday |
| February 29, 2004 | 22 years, 7 months, 7 days | March 1, 2027 | Monday |
How Many Seconds Are in a Year?
Seconds are built up from minutes, hours and days. A day has 86,400 seconds, and a normal year has 31,536,000. Use these figures to check your own total or to plan a milestone.
| Time unit | Seconds |
|---|---|
| 1 minute | 60 |
| 1 hour | 3,600 |
| 1 day | 86,400 |
| 1 week | 604,800 |
| 1 year (365 days) | 31,536,000 |
| 1 leap year (366 days) | 31,622,400 |
| 1,000,000,000 seconds | About 31 years, 8 months |
Birthday Milestones
Besides the yearly birthday, a few milestones are fun to mark. Your 10,000th day arrives at about 27 years and 4 months of age, and your 1,000,000,000th second at about 31 years and 8 months. The Birthday Fact box shows the date you reach one billion seconds, or the date you passed it.
Related Date Tools
For the difference in days between any two dates, use the days between dates calculator. To get your age in years, months and days at any past or future date, try the age calculator. The date calculator adds or subtracts days, weeks, months or years, and the time calculator and hours calculator handle clock time.
Limits of This Calculator
The countdown uses the clock and time zone on your device, so the seconds follow your local time. Daylight saving changes can shift the number of hours by one on the day of the change. The calculator uses the Gregorian calendar and works for birth dates from 1900 onward.
Who Can Use This Calculator?
Anyone curious about their next birthday, parents tracking a child's age, people planning a party, and fans of fun date facts such as how many seconds old they are.
How to Use This Birthday Calculator
Enter your date of birth
Pick the day, month and year you were born. Add the time of birth if you know it.
Choose how many birthdays to list
Use the slider to show your next 1 to 10 birthdays and their weekdays.
Watch the live countdown
See the days, hours, minutes and seconds until your next birthday, and the seconds you have lived so far.
Copy the result
Press Copy Result to share your countdown or age, or Reset to try another date.