Supporting yourself against a wall, lift up the toes and press them against the wall, stretching the underside of the foot. Lean the hips towards the wall to progress the stretch.
Calf – Gatrocnemius
Standing or supporting yourself against a wall, take a step back, bend the front knee and keep the back leg straight with heel on the ground. Make sure the back foot is facing forwards (not out to the side). Push forwards and feel the stretch in the back of the straight leg from knee into calf.
Calf – Soleus
As with Gastrocnemius, but bend the back knee, keeping the heel on the ground. Make sure the back foot is facing forwards (not out to the side). Feel the stretch in the lower calf/Achilles.