Compound leg exercises like squats and leg presses don't actually build much calf muscle because of how your body mechanics work and how little they activate that specific muscle. To really grow your calves, you need to do exercises that target them directly instead of relying on big compound movements.

Compound lower-body exercises performed through a full range of motion (e.g., squats) induce greater hypertrophy in the distal regions of mono-articular quadriceps muscles (e.g., vastus lateralis) compared to isolation exercises, likely due to training at longer muscle lengths.

Isolation exercises targeting a single joint (e.g., leg extensions) produce greater hypertrophy in bi-articular muscles (e.g., rectus femoris) compared to multi-joint compound movements (e.g., squats) due to avoidance of active insufficiency.

Pushing a heavy leg press machine makes the outer part of your thigh muscle grow more than doing leg extensions, because it puts more overall stress on that part of the muscle.

Doing calf raises while standing builds more calf muscle than doing them while sitting. This happens because changing the angle of your knee changes how much your calf muscles grow, making standing calf raises much more effective for building size.

If you're new to working out, doing leg presses twice a week might build more leg muscle in less time than just doing knee extensions, because leg presses work more muscles at once — like your quads, butt, and inner thighs.