Probably the best calf stretch ever!
Try to get into the habit of doing this stretch daily at your front door
When you are not warmed up: holding on, standing tall & straight, hips square to the front, standing on the step take both heels off the step and gently alternate pushing your heels down and keep this moving (gently as you are not warmed up)so it is a dynamic calf stretch.
When you are warmed up eg: after a walk or run: holding on, standing tall & straight, hips square to the front, put both feet onto the step, then take one heel off and gently sink your weight into that heel, hold for about 30 seconds then change heels. The more you let your weight sink down the deeper the stretch
Calf stretches are great if you are walking, running, dancing or wearing high heels