What is Dimensional Formula of Frequency?

Frequency is the defined as number of complete cycles per second.

Mathematically,
Frequency = number of vibrations/sec

Dimensional Formula of Time = M⁰L⁰T¹

Putting these values in above equation we get
Dimensional Formula of Frequency = 1/ M⁰L⁰T¹ = M⁰L⁰T^-1

Hence,
Dimensional Formula of Frequency = M⁰L⁰T^-1
SI unit of Frequency is the hertz.