Age Calculator

How this calculator works

This age calculator compares your date of birth to today’s date and computes the difference by counting full years first, then full months, and finally the remaining days.

Formula used

There isn’t a single closed-form formula because month lengths vary. The calculation is done by:

• Start with year difference, month difference, and day difference.
• If days are negative, borrow days from the previous month.
• If months are negative, borrow 12 months from the year difference.

Example calculation

If your date of birth is 2000-06-10 and today is 2026-01-15, the result will be expressed as full years, then the remaining months, then remaining days.

FAQs

• Why do I see months and days instead of only total days? This format is easier to interpret and matches how age is commonly described.
• What if I enter a future date? The calculator will show an error because a date of birth can’t be in the future.
• Does it account for leap years? Yes—borrowing days from the previous month naturally includes leap-year month lengths.