Fortunately, there is a simple stretch you can use to improve the tightness of your calves. But I use the word stretch hesitantly, because the calves are NOT too short in need of being stretched longer. Instead, they are too tense and in need of relaxing. So when we stretch our calves (or anything else in the body) we want to relax them, not rip them apart. Almost all of us overstretch when we stretch, and this makes our calves even tighter.
The video below walks you through this basic calf stretch. We should all do it daily.