Calculate age from date of birth.
Enter a valid date of birth.
Age = Current date − Date of birth, adjusted for whether the birthday has occurred this year.The calculator applies the formula shown below and rounds the displayed answer for readability. Institutional grading rules, date conventions or required decimal precision may differ, so users should follow the rule used by their school, employer or form.
Age Calculator applies a common arithmetic or academic relationship to the values entered. Calculate age from date of birth. It can be used to check manual work and understand how each input affects the result.
It is an estimate generated from the values entered on this page and the calculation method shown in the formula and methodology sections.
The calculator validates the entered values, applies the protected formula shown on the page and then rounds only the displayed result where appropriate.
Use current source values, confirm units and time periods, include every requested cost or measurement, and avoid rounding inputs before the final calculation.
Different calculators may use different assumptions, time periods, rounding rules, reference standards or included costs. Compare the inputs and limitations before comparing answers.
Use it as a calculation check or planning estimate. Follow the precision, grading, reporting or date convention required by the relevant organization.
Recalculate whenever a material input changes, such as a rate, price, balance, measurement, time period, fee, contribution or project dimension.
Enter a simple known case first to confirm the expected result, then calculate the real values. Keep the same units and avoid rounding intermediate values when precision matters.
Age is calculated between a birth date and a selected reference date. Completed years change only when the birthday has occurred in the reference year. Day and month totals depend on calendar length and leap years.
Eligibility rules may use age on a fixed cut-off date, age at the start of an academic year or another legal definition. Use the reference date required by the institution rather than assuming today is always correct.
A date of birth can be personal information. Use the calculator locally and verify official age requirements with the relevant form, authority or institution.