Seated Heel Raises

The calf muscle is actually "muscleS".  The calf muscle is made up of the gastrocnemius and soleus muscle group.  Both are involved in helping you point your toe and/or stand on your tippy-toes.  The Soleus is more active when your knee is bent. 

There is a machine at most gyms that you can sit in with your knees bent and lift weights to strengthen this muscle.  The video shown here is how you do the exercise in the comfort of your own home.  The video has a friend doing the exercise with weights on her knees.  You can do it with or without weight.

Start with no weight and do 30.  When you can do 30 repetitions easily, it is time to add more weight!

Good luck!