Time
Age Calculator
How to use this age calculator
- Enter the requested values in the calculator.
- Review the result immediately below the fields.
- Use the explanation and example below to check how the result was obtained.
Method and formula
Enter a birth date and an as-of date. The calculator counts complete calendar years first, then complete months, and finally the remaining days.
Worked example
Someone born on March 10, 2000 is 25 years old on March 10, 2025. One day earlier, the completed age is still 24 years.
What the result does not include
Calendar months have different lengths, so a month is not treated as a fixed number of days. Time zones and the time of day are not included.
Frequently asked questions
Are the calculations saved?
No. The calculation runs in your browser. This site does not receive or store the numbers and dates entered into a calculator.
Why can another calculator show a slightly different result?
Results can differ because of rounding, input units, timing assumptions, or extra fees and variables. Keep full precision until the final step and compare the assumptions used by each source.
Can I use this result for an official decision?
Use it as an educational estimate and a way to check your own arithmetic. For medical, financial, academic, or legal decisions, confirm the result with the relevant professional or institution.