About this age calculator
Calculate elapsed calendar years, months, and days between a birth date and a comparison date. The comparison defaults to today on your device, but you can choose another date to check an anniversary or a form requirement. The result also reports days until the next birthday. Dates are handled as calendar values, so daylight-saving changes do not add or remove an hour from the calculation.
How it works
Whole years and months are counted using calendar anniversaries. When a day does not exist in a destination month it is clamped to that month’s last day. Remaining days use UTC date differences.
Try these examples
2000-01-15 to 2026-09-12
26 years, 7 months, 28 days
2000-02-29 to 2025-02-28
25 years, 0 months, 0 days
Limitations & privacy
Birth dates must be from 1900 onward. February 29 birthdays use February 28 in non-leap years. This convention may differ from legal age rules in your location.
Inputs and results stay in this browser. Only tool identifiers are stored for your recently used tools. You can clear that history from the directory.
A few good questions
Can I compare against a future date?
Yes. Enter that date in the comparison field.
How are leap-day birthdays handled?
February 28 is used in years without February 29.
Does time of birth matter?
No. This tool compares whole calendar dates, not timestamps.
Updated September 12, 2026