There are 640 muscles in the human body. Depending on what the activities are for an individual each day, one can estimate how many muscles are used. A sedentary individual would obviously use fewer muscles than a very active person. Our survival depends on our ability to adapt to the environment and this is where muscles and movement come in to the picture. Skeletal muscles produce movement. Heat production is another function of skeletal muscles and maintain homeostasis of temperature. Posture is affected also.
It depends on what the person does on that day. Some my use less than 100 of their muscles daily while other might use more than 200 of their muscles.