A photo caption needs the person's age when the picture was taken. The date the image was uploaded can give a different answer, particularly near a birthday.
Use the capture date you can support
Enter Date of Birth as 2000-06-18 and Calculate Age As Of as 2025-06-17. The result is 24 years, 11 months, and 30 days. Change the reference date to June 18 and it becomes 25 years, zero months, and zero days.
This example illustrates why “2025 minus 2000” can overstate age. The birthday had not occurred on June 17. The calculator counts completed calendar anniversaries before it counts the remaining months and days.
If the photo date is uncertain
Check the album label or the original file's information. If you can establish only the month, calculate the first and last plausible dates and use wording that preserves the uncertainty. Do not present an exact age based on an exact date you guessed.
The tool takes whole calendar dates. If the photo was taken while traveling close to midnight, use the local date you intend the caption to describe. File metadata may use a different time zone.
A reference date before birth is rejected. If that happens with a family photo, check whether you selected the right person or transcribed the year correctly before trying again.