If someone asks how old you are, the usual answer is completed years. A scrapbook entry or a personal milestone might call for years, months, and days. Those figures depend on the calendar. A year can contain 365 or 366 days, and a month can contain 28 through 31 days, so dividing a day total by average month length gives a different kind of answer.
Set the date you want to measure
- Enter the complete date of birth.
- Set Calculate Age As Of to the day you want to describe. For a keepsake from a previous visit, use the visit date.
- Read Years, Months, and Days together. Use Total Days Lived for a straight count across the whole interval.
- If the birthday is February 29, choose how to observe it in common years.
Follow the calendar anchors
Start at the birth date and count full birthday anniversaries through the reference date. From the last completed birthday, count full months using the same day of the month where it exists. When it does not, use the final day of that month. Count the days left after the last monthly anchor. The app counts whole weeks by dividing elapsed days by seven and rounding down.
Try a month-end example
Someone born January 31, 2000 is 24 years and one month old on February 29, 2024 under the month-end rule. January 31 plus one calendar month lands on February 29 that year. On March 1 the result is 24 years, one month, and one day. In 2023 that February anchor would have been February 28. You can reproduce both results by changing only the reference date.
Watch for a different counting question
“Which day of life is this?” includes the day of birth as day one. “How many days have elapsed?” begins at zero. When copying a figure, preserve the label. Also check the order of the input dates. A photograph’s upload date may be later than the day the photo was taken, and it is the actual photo date that belongs in an age caption.
FAQ
Can I calculate an age for a future birthday?
Yes. Enter the future date as the reference date. The result is relative to that date.
Can I calculate exact age from a month and day alone?
The birth year is needed for age. With only a month and day, use the birthday countdown.