Use formula

$f_{out} = \frac {f_{in}}{mod – n}$

where,

$f_{out} = $ Output frequency

$f_{in} \ = $ Input frequency

$mod – n = $ Modulus of counter

$f_{out} = \frac {f_{in}}{mod – n}$

where,

$f_{out} = $ Output frequency

$f_{in} \ = $ Input frequency

$mod – n = $ Modulus of counter