High School and College Formulas
High School Graduation Year to Age Formula
Estimated birth year = Graduation year − 17 to 18.
Estimated current age = Current year − Estimated birth year.
College Graduation Year to Age Formula
For a four-year college, the typical starting assumption is graduation at age 21 to 22. A gap year, transfer, part-time study, or an accelerated program can shift the estimate.
School Age and Graduation Year From Date of Birth
Use the school timeline mode when a date of birth is known. September 1 is a common cutoff example, but rules vary by state and district.