If you are looking to add mass to your calf muscles, it is important that you work your entire lower leg. Building mass requires that you do the right technique and use the correct weight. I would suggest doing 4 set of 10 reps for each exercise.
3 Best Calf Exercises to Build Mass
1. Calf Press On The Leg Press Machine
Exercise Data
Main Muscle Worked: Calves
Other Muscles Worked: None
Equipment: Machine
Mechanics Type: Isolation
Procedure: While sitting a leg press machine, press the weight rack up as if you were going to do a leg press. Lock your knees and slide your feet down so that only the balls of your feet are on the rack and your heels are hanging off. Push with your toes and point the feet like a ballet stance, pushing the rack along with you. Let the rack come back down bringing the toes closer to your body and repeat. Make sure the handles remain in the locked position. If your feet were to slip off the rack and you don't have the handles locked you can be injured. Don't bounce the rack up and down. Use the muscles slowly with control. You can also focus on the inner or outer calves by pointing your toes in or out instead of keeping them straight.
2. Calf Raise On A Dumbbell
Exercise Data
Main Muscle Worked: Calves
Other Muscles Worked: None
Equipment: Dumbbell
Mechanics Type: Isolation
Procedure: When doing one-legged calf raises, stand on a dumbell handle (preferably one with round plates so it rolls). This tendency to roll will make you work to stabilize yourself as you're doing the calf raise, increasing the effectiveness of the exercise.
Be sure to hang onto something solid as you're doing this exercise as you don't want to slip off. The tendency for the dumbell to roll will allow you to roll your foot over the top of the handle, giving you full extension of the calf at the top. As you come up, roll the dumbell slightly backward. Roll it slightly forward as you come down to get a better stretch. You can also do these standing on the actual dumbbell plate, using a large 85 pound dumbbell that is wider.
3. Hack Squat machine Calf Raises
Using a hack squat machine, position yourself as you normally would if you were performing a regular hack squat. Place your toes at the bottom of the hack squat platform so that your toes are placed on the bottom edge and your heels are hanging over the edge. Begin by pushing your toes down so that your heels become raised so that you are on your toes. Squeeze your calves at the top of this movement for a one-count. Return to the start position and repeat until failure.
There are exercises variations you can make to target specific parts of your calves.
If you position your feet inwards, you can focus on your inner calves. Positioning your feet outwards works your outer calves.