There is no strict rule that binds a devotee; Lord Hanuman values true devotion and pure intent above numbers. However, depending on your spiritual goals and the severity of the problems you are facing, the scriptures and sages recommend specific counts.
Chanting it once every morning or evening is perfect for maintaining general peace, mental clarity, and daily protection. It takes only 3 to 5 minutes but sets a positive tone for the entire day.
Many devotees chant it 7 times consecutively on Tuesdays or Saturdays. This is often done to overcome the malefic effects of planets (specifically Saturn/Shani or Mars/Mangal) and to remove specific minor hurdles.
Chanting the Chalisa 11 times a day for a set number of days (usually 11, 21, or 41 days) is known as a Sankalp. This intense practice is undertaken when a person is facing severe life crises—such as severe illness, major financial ruin, or deep depression.
The Chalisa itself states: "Jo Sat Baar Paath Kar Koi, Chhutahi Bandi Maha Sukh Hoi." (Whoever recites it a hundred times is freed from the bondage of life and attains great bliss). Chanting it 100 times requires immense dedication and usually takes around 5-6 hours. It is considered a supreme spiritual austerity (Tapasya).