=COUNTIF(CalculatedAgeRange,"="&X2)-COUNTIF(CalculatedAgeRange,""&Y2)

where X2 houses a value like 30 and Y2 40. This calculates an inclusive
count.

lisaw wrote:
I am trying to work out a spreadsheet formula for calculating if an age
range is between two values say between 30 and 40.

Using DATEDIF the age column is formated as a number and is based on
another column called Date of birth.

Can the countif take multiple criteria?