Age Calculator US
Calculate exact age in years, months and days from a date of birth.
How it works
Enter a date of birth and an "as of" date to get exact age in years, months and days, plus the total in days and weeks.
Frequently asked questions
How is exact age calculated?
We count complete years from the date of birth to today, then the remaining months and days, accounting for different month lengths and leap years.
Can I calculate age on a future date?
Yes — change the "as of" date to any date and the result updates to the age on that day.
Age Calculator
Find out exactly how old you are — or how old anyone is — in years, months and days. Enter a date of birth and, if you like, a second date to measure to, and this calculator works out the precise age down to the day. It is handy for anyone in United States filling in forms, checking eligibility dates or simply settling a "how old is...?" question.
How to use the age calculator
Pick the date of birth using the date picker. By default the age is measured up to today, but you can set any target date to find an age on a past or future day. The result updates instantly and shows the full breakdown in years, months and days, plus the total number of days lived.
Common uses
- Check an exact age for school, pension or benefit eligibility in United States.
- Work out how many days until a birthday or milestone.
- Find someone's age on a specific historical or future date.
- Calculate the gap in age between two people.
More questions
How is age in months and days calculated?
The calculator counts complete years first, then the remaining whole months, then the leftover days — accounting for different month lengths and leap years so the figure is accurate.
Does it handle leap years?
Yes. February 29 birthdays and leap-year day counts are handled correctly, so the total days lived is exact.
Results are estimates for general guidance in United States and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.