In column K I have ages calculated from birthdates.

In Column L I would like to translate these ages into age groups, from which
I will later create a pivot chart to show the frequency of each age group.

I need a formula to translate the ages in Column K into age ranges in Column
L (16-20, 21-30, 31-40, 41-50, 51-60, 61-70, 71-80).

Can anyone tell me in layman's terms how this can be done and what I need to
enter where?

Thanks for reading!