How your age in days is worked out
The calculator counts the time between your birth and this moment and splits it into whole days. It uses real calendar dates, so every 29 February you've lived through is included automatically. If we don't know what time you were born, we assume midday, which means your count ticks over at noon.
Working it out by hand
Multiply your age in years by 365, add one day for every leap day you've lived through, then add the days since your last birthday. Someone who turns 30 today and has lived through seven leap days is 30 × 365 + 7 = 10,957 days old.
Ages in days
How many days old you are on some common birthdays. There are two possible answers for most ages because it depends on how many leap days fell in between.
| Birthday | Days old |
|---|---|
| 1st | 365 or 366 |
| 10th | 3,652 or 3,653 |
| 18th | 6,574 or 6,575 |
| 21st | 7,670 or 7,671 |
| 25th | 9,131 or 9,132 |
| 30th | 10,957 or 10,958 |
| 40th | 14,610 |
| 50th | 18,262 or 18,263 |
| 60th | 21,915 |
| 70th | 25,567 or 25,568 |
| 80th | 29,220 |
Day milestones worth marking
Round numbers of days land at ages nobody normally celebrates. You reach 1,000 days just before you're 2 years and 9 months old, and 10,000 days at about 27 years and 4½ months. Day 20,000 arrives at about 54 years and 9 months.
Questions
Does the day I was born count as day one?
Not here. Like your age in years, the count starts at zero: you're 0 days old on the day you're born and 1 day old the next day. If you count your birth day as day one, add one to the total.
How many seconds old am I?
About 31.6 million for every year you've been alive. The calculator above shows the exact figure counting live, and you can find out when you'll pass a billion seconds.
Is my birth date stored anywhere?
Only in your own browser, so you don't have to type it again on other pages of this site. It's never sent to us or anyone else.